82 research outputs found
An intercomparison of remote sensing river discharge estimation algorithms from measurements of river height, width, and slope
The Surface Water and Ocean Topography (SWOT) satellite mission planned for launch in 2020 will map river elevations and inundated area globally for rivers >100 m wide. In advance of this launch, we here evaluated the possibility of estimating discharge in ungauged rivers using synthetic, daily ‘‘remote sensing’’ measurements derived from hydraulic models corrupted with minimal observational errors. Five discharge algorithms were evaluated, as well as the median of the five, for 19 rivers spanning a range of hydraulic and geomorphic conditions. Reliance upon a priori information, and thus applicability to truly ungauged reaches, varied among algorithms: one algorithm employed only global limits on velocity and depth, while the other algorithms relied on globally available prior estimates of discharge. We found at least one algorithm able to estimate instantaneous discharge to within 35% relative root-mean-squared error (RRMSE) on 14/16 nonbraided rivers despite out-of-bank flows, multichannel planforms, and backwater effects. Moreover, we found RRMSE was often dominated by bias; the median standard deviation of relative residuals across the 16 nonbraided rivers was only 12.5%. SWOT discharge algorithm progress is therefore encouraging, yet future efforts should consider incorporating ancillary data or multialgorithm synergy to improve results
The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry
Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes
PLASTICITY OF CELL MEMBRANES: MODIFICATION OF CELL SURFACES OF NORMAL AND SPONTANEOUSLY-TRANSFORMED ASTROBLASTS IN RESPONSE TO ALCOHOL TREATMENT
Ethanolamine base exchange enzymatic activities in spontaneous transformed glial cell lines Effect of dibutyryl cyclic AMP treatment
AbstractCultured astrocytes derived from neonatal rats (normal cells) displayed maximal ethanolamine base exchange enzymatic activity (EBEE) when cultures reached confluency and cells almost ceased to divide. At this stage, ethanolamine phosphotransferase (EPT) and choline base exchange enzyme (CBEE) activities reached a plateau. In spontaneously transformed glial cells, no differential activity variation either between EPT and CBEE, or between EPT and EBEE was observed. The EBEE activity was mainly localized in the microsomal fraction and was completely absent from plasma membranes. Dibutyryl cyclic AMP (db-cAMP) treatment of the transformed cells reversed the pattern of these activities to that of normal cells. Moreover, treatment of the transformed cells with medium conditioned by normal astroblasts markedly increased EBEE activity. This study demonstrates that (i) variation of EBEE activity during cell growth differs in normal and in transformed cultured glial cells. (ii) EBEE activity may be modulated via both db-cAMP and normal cell conditioned medium. Our findings suggest a possible implication of EBEE in the maturation and contact inhibition of cell growth
S-22-3 Oxysterol (7β-hydroxycholesteryl-3-oleate) promotes serotonergic reinnervation in the lesioned rat spinal cord by reducing glial reaction
Modification of Plasma Membrane DT-Diaphorase Activity Upon Transformation: A Comparison between Astrocytes in Primary Culture and C6 Glioblastoma Cells
Effect of 7β-hydroxycholesterol on growth and membrane composition of Mycoplasma capricolum
Abstract7β-OH cholesterol in a cholesterol rich growth medium (5–10 μg/ml) extended the lag period and slowed down the growth rate of Mycoplasma capricolum cells. In a cholesterol poor medium (0.5 μg/ml) inadequate to support growth, 7β-OH cholesterol exerts a synergistic effect on growth. The 7β-OH cholesterol was incorporated unchanged from the growth medium and could be recovered exclusively in the membrane fraction. The incorporation of the 7β-OH cholesterol has no effect on the total phospholipid content but the DPG to PG ratio was markedly decreased. Exchange studies with lipid vesicles revealed that whereas most of the cholesterol underwent exchange, only about 20% of the 7β-OH cholesterol was exchanged
Effect of 7β-hydroxycholesterol on astrocyte primary cultures and derived spontaneously transformed cell lines Cytotoxicity and cholesterogenesis
AbstractThe correlation between the lethal effect of 7β-hydroxycholesterol (7β-OH-CH) on spontaneously transformed cell lines derived from rat astrocyte primary cultures (normal cells) and de novo cholesterogenesis was investigated. Both 7β-OH-CH and 7-keto-CH were not cytotoxic on normal cells but 7β-OH-CH affected markedly the viability of the transformed cells. The use of [14C]acetate or [14C] mevalonate indicated that 7-keto-CH inhibits de novo cholesterogenesis upstream of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) in both cell types whereas 7β-OH-CH also inhibits downstream of HMGR. The accumulation of two radiolabelled products X1 and X2 between mevalonate and CH was found in unsaponifiable neutral lipids extracted from 7β-OH-CH treated transformed cells. HPLC and GC-MS revealed that X1 and X2 are not lanosterol anti 24.25-epoxylanosterol, respectively. Incubation of the transformed cells with X1 and X2 did not affect their viability. Our data demonstrate that, under our experimental conditions, 7β-OH-CH cytotoxicity is not linked to the inhibition of de novo cholesterogenesis in cultured glial transformed cells
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