935 resultados para TRANSIENT ABSORPTION


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Acquired Fanconi syndrome is characterized by inappropriate urinary loss of amino acids, bicarbonate, electrolytes, and water. It has recently been described in dogs fed chicken jerky treats from China, a new differential diagnosis to the classical inciting infectious diseases (e.g. leptospirosis, pyelonephritis) and toxins. A dog fed exclusively chicken jerky treats purchased in Switzerland was presented to our clinic with severe polyuria, polydipsia and profound electrolyte and acid base disturbances. Other inciting causes of Fanconi syndrome were ruled out. The requirement of a very intensive supportive treatment in this dog stands in contrast to treatment of chronic forms of Fanconi syndrome as described in the Basenji. This intensive therapy and the associated monitoring can be a real challenge and a limiting factor for the prognosis of acquired Fanconi syndrome. Veterinarians should be aware of the risk of excessive feeding of chicken jerky treats.

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BACKGROUND AND PURPOSE To assess the association of lesion location and risk of aspiration and to establish predictors of transient versus extended risk of aspiration after supratentorial ischemic stroke. METHODS Atlas-based localization analysis was performed in consecutive patients with MRI-proven first-time acute supratentorial ischemic stroke. Standardized swallowing assessment was carried out within 8±18 hours and 7.8±1.2 days after admission. RESULTS In a prospective, longitudinal analysis, 34 of 94 patients (36%) were classified as having acute risk of aspiration, which was extended (≥7 days) or transient (<7 days) in 17 cases. There were no between-group differences in age, sex, cause of stroke, risk factors, prestroke disability, lesion side, or the degree of age-related white-matter changes. Correcting for stroke volume and National Institutes of Health Stroke Scale with a multiple logistic regression model, significant adjusted odds ratios in favor of acute risk of aspiration were demonstrated for the internal capsule (adjusted odds ratio, 6.2; P<0.002) and the insular cortex (adjusted odds ratio, 4.8; P<0.003). In a multivariate model of extended versus transient risk of aspiration, combined lesions of the frontal operculum and insular cortex was the only significant independent predictor of poor recovery (adjusted odds ratio, 33.8; P<0.008). CONCLUSIONS Lesions of the insular cortex and the internal capsule are significantly associated with acute risk of aspiration after stroke. Combined ischemic infarctions of the frontal operculum and the insular cortex are likely to cause extended risk of aspiration in stroke patients, whereas risk of aspiration tends to be transient in subcortical stroke.

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BACKGROUND AND PURPOSE Copeptin has been associated with recurrent cerebrovascular events after transient ischemic attack (TIA). In an independent cohort, we evaluated copeptin for the prediction of recurrent cerebrovascular events within 3 months after TIA and assessed the incremental value of copeptin compared with the ABCD2 (age, blood, clinical features of TIA, duration of symptoms, presence of diabetes mellitus) and ABCD3-I (ABCD2, dual TIA [the presence of ≥2 TIA symptoms within 7 days], imaging [the presence of abnormal findings on neuroimaging]) scores. METHODS This prospective, multicenter cohort study was conducted at 3 tertiary Stroke Centers in Switzerland and Germany. RESULTS From March 2009 through April 2011, we included 302 patients with TIA admitted within 24 hours from symptom onset. Of 28 patients with a recurrent cerebrovascular event within 3 months (stroke or TIA), 11 patients had a stroke. Although the association of copeptin with recurrent cerebrovascular events was not significant, the association with stroke alone as end point was significant. After adjusting for the ABCD2 score, a 10-fold increase in copeptin levels was associated with an odds ratio for stroke of 3.39 (95% confidence interval, 1.28-8.96; P=0.01). After addition of copeptin to the ABCD2 score, the area under the curve of the ABCD2 score improved from 0.60 (95% confidence interval, 0.46-0.74) to 0.74 (95% confidence interval, 0.60-0.88, P=0.02). In patients with MRI (n=223), the area under the curve of the ABCD3-I score increased in similar magnitude, although not significantly. Based on copeptin, 31.2% of patients were correctly reclassified across the risk categories of the ABCD2 score (net reclassification improvement; P=0.17). CONCLUSIONS Copeptin improved the prognostic value of the ABCD2 score for the prediction of stroke but not TIA, and it may help clinicians in refining risk stratification for patients with TIA. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT00878813.

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BACKGROUND AND PURPOSE Visit-to-visit variability in systolic blood pressure (SBP) is associated with an increased risk of stroke and was reduced in randomized trials by calcium channel blockers and diuretics but not by renin-angiotensin system inhibitors. However, time of day effects could not be determined. Day-to-day variability on home BP readings predicts stroke risk and potentially offers a practical method of monitoring response to variability-directed treatment. METHODS SBP mean, maximum, and variability (coefficient of variation=SD/mean) were determined in 500 consecutive transient ischemic attack or minor stroke patients on 1-month home BP monitoring (3 BPs, 3× daily). Hypertension was treated to a standard protocol. Differences in SBP variability from 3 to 10 days before to 8 to 15 days after starting or increasing calcium channel blockers/diuretics versus renin-angiotensin system inhibitors versus both were compared by general linear models, adjusted for risk factors and baseline BP. RESULTS Among 288 eligible interventions, variability in SBP was reduced after increased treatment with calcium channel blockers/diuretics versus both versus renin-angiotensin system inhibitors (-4.0 versus 6.9 versus 7.8%; P=0.015), primarily because of effects on maximum SBP (-4.6 versus -1.0 versus -1.0%; P=0.001), with no differences in effect on mean SBP. Class differences were greatest for early-morning SBP variability (3.6 versus 17.0 versus 38.3; P=0.002) and maximum (-4.8 versus -2.0 versus -0.7; P=0.001), with no effect on midmorning (P=0.29), evening (P=0.65), or diurnal variability (P=0.92). CONCLUSIONS After transient ischemic attack or minor stroke, calcium channel blockers and diuretics reduced variability and maximum home SBP, primarily because of effects on morning readings. Home BP readings enable monitoring of response to SBP variability-directed treatment in patients with recent cerebrovascular events.

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Transient exposure of brown trout embryos from fertilization until hatch (70 days) to 17β-estradiol (E2) was investigated. Embryos were exposed to 3.8 and 38.0 ng/L E2 for 2h, respectively, under four scenarios: (A) exposure once at the day of fertilization (0 days post-fertilization, dpf), (B) once at eyeing stage (38 dpf), (C) weekly exposure until hatch or (D) bi-weekly exposure until hatch. Endpoints to assess estrogen impact on embryo development were fertilization success, chronological sequence of developmental events, hatching process, larval malformations, heart rate, body length and mortality. Concentration-dependent acceleration of development until median hatch was observed in all exposure scenarios with the strongest effect observed for embryos exposed once at 0 dpf. In addition, the hatching period was significantly prolonged by 4-5 days in groups receiving single estrogen exposures (scenarios A and B). Heart rate on hatching day was significantly depressed with increasing E2 concentrations, with the strongest effect observed for embryos exposed at eyeing stage. Estrogenic exposure at 0 dpf significantly reduced body length at hatch, not depending on whether this was a single exposure or the first of a series (scenarios A and D). The key finding is that even a single, transient E2 exposure during embryogenesis had significant effects on brown trout development. Median hatch, hatching period, heart rate and body length at hatch were found to be highly sensitive biomarkers responsive to estrogenic exposure during embryogenesis. Treatment effects were observable only at the post-hatch stage.

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Although beryllium-10 (10Be) concentrations in stream sediments provide useful synoptic views of catchment-wide erosion rates, little is known on the relative contributions of different sediment supply mechanisms to the acquisition of their initial signature in the headwaters. Here we address this issue by conducting a 10Be-budget of detrital materials that characterize the morphogenetic domains representative of high-altitude environments of the European Alps. We focus on the Etages catchment, located in the Ecrins-Pelvoux massif (southeast France), and illustrate how in situ 10Be concentrations can be used for tracing the origin of the sand fraction from the bedload in the trunk stream. The landscape of the Etages catchment is characterized by a geomorphic transient state, high topographic gradients, and a large variety of modern geomorphic domains ranging from glacial environments to scarcely vegetated alluvial plains. Beryllium-10 concentrations measured in the Etages catchment vary from similar to 1 x 104 to 4.5 x 105 atoms per gram quartz, while displaying consistent 10Be signatures within each representative morphogenetic unit. We show that the basic requirements for inferring catchment-wide denudation from 10Be concentration measurements are not satisfied in this small, dynamic catchment. However, the distinct 10Be signature observed for the geomorphic domains can be used as a tracer. We suggest that a terrestrial cosmogenic nuclide (TCN) budget approach provides a valuable tool for the tracing of material origin in basins where the let nature do the averaging' principles may be violated.

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BACKGROUND Hemodialysis patients are high absorbers of intestinal cholesterol; they benefit less than other patient groups from statin therapy, which inhibits cholesterol synthesis. OBJECTIVES This study sought to investigate whether the individual cholesterol absorption rate affects atorvastatin's effectiveness to reduce cardiovascular risk in hemodialysis patients. METHODS This post-hoc analysis included 1,030 participants in the German Diabetes and Dialysis Study (4D) who were randomized to either 20 mg of atorvastatin (n = 519) or placebo (n = 511). The primary endpoint was a composite of major cardiovascular events. Secondary endpoints included all-cause mortality and all cardiac events. Tertiles of the cholestanol-to-cholesterol ratio, which is an established biomarker of cholesterol absorption, were used to identify high and low cholesterol absorbers. RESULTS A total of 454 primary endpoints occurred. On multivariate time-to-event analyses, the interaction term between tertiles and treatment with atorvastatin was significantly associated with the risk of reaching the primary endpoint. Stratified analysis by cholestanol-to-cholesterol ratio tertiles confirmed this effect modification: atorvastatin reduced the risk of reaching the primary endpoint in the first tertile (hazard ratio [HR]: 0.72; p = 0.049), but not the second (HR: 0.79; p = 0.225) or third tertiles (HR: 1.21; p = 0.287). Atorvastatin consistently significantly reduced all-cause mortality and the risk of all cardiac events in only the first tertile. CONCLUSIONS Intestinal cholesterol absorption, as reflected by cholestanol-to-cholesterol ratios, predicts the effectiveness of atorvastatin to reduce cardiovascular risk in hemodialysis patients. Those with low cholesterol absorption appear to benefit from treatment with atorvastatin, whereas those with high absorption do not benefit.

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Information on the relationship between cumulative fossil CO2 emissions and multiple climate targets is essential to design emission mitigation and climate adaptation strategies. In this study, the transient response of a climate or environmental variable per trillion tonnes of CO2 emissions, termed TRE, is quantified for a set of impact-relevant climate variables and from a large set of multi-forcing scenarios extended to year 2300 towards stabilization. An  ∼ 1000-member ensemble of the Bern3D-LPJ carbon–climate model is applied and model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte Carlo-type framework. Uncertainties in TRE estimates include both scenario uncertainty and model response uncertainty. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.9 °C (68 % confidence interval (c.i.): 1.3 to 2.7 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and a steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic meridional overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The constrained model ensemble is also applied to determine the response to a pulse-like emission and in idealized CO2-only simulations. The transient climate response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the equilibrium climate sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

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BACKGROUND Temporary increases in plasma HIV RNA ('blips') are common in HIV patients on combination antiretroviral therapy (cART). Blips above 500 copies/mL have been associated with subsequent viral rebound. It is not clear if this relationship still holds when measurements are made using newer more sensitive assays. METHODS We selected antiretroviral-naive patients that then recorded one or more episodes of viral suppression on cART with HIV RNA measurements made using more sensitive assays (lower limit of detection below 50 copies/ml). We estimated the association in these episodes between blip magnitude and the time to viral rebound. RESULTS Four thousand ninety-four patients recorded a first episode of viral suppression on cART using more sensitive assays; 1672 patients recorded at least one subsequent suppression episode. Most suppression episodes (87 %) were recorded with TaqMan version 1 or 2 assays. Of the 2035 blips recorded, 84 %, 12 % and 4 % were of low (50-199 copies/mL), medium (200-499 copies/mL) and high (500-999 copies/mL) magnitude respectively. The risk of viral rebound increased as blip magnitude increased with hazard ratios of 1.20 (95 % CI 0.89-1.61), 1.42 (95 % CI 0.96-2.19) and 1.93 (95 % CI 1.24-3.01) for low, medium and high magnitude blips respectively; an increase of hazard ratio 1.09 (95 % CI 1.03 to 1.15) per 100 copies/mL of HIV RNA. CONCLUSIONS With the more sensitive assays now commonly used for monitoring patients, blips above 200 copies/mL are increasingly likely to lead to viral rebound and should prompt a discussion about adherence.

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Polyvinylpyrrolidone (PVP) can act as potential drug delivery vehicle for porphyrin-based photosensitizers in photodynamic therapy (PDT) to enhance their stability and prevent porphyrin self-association. In the present study the interactions of PVP (MW 10 kDa) were probed with five different derivatives of chlorin e6 (CE6) bearing either one of the amino acids serine, lysine, tyrosine or arginine, or monoamino-hexanoic acid as substituent. All derivatives of CE6 (xCE) formed aggregates of a similar structure in aqueous buffer in the millimolar range. In the presence of PVP monomerization of all xCE aggregates could be proved by 1H NMR spectroscopy. xCE-PVP complex formation was confirmed by 1H NMR T2 relaxation and diffusion ordered spectroscopy (DOSY). 1H1H-NOESY data suggested that the xCE uptake into the PVP polymer matrix is governed by hydrophobic interactions. UV–vis absorption and fluorescence emission bands of xCE in the micromolar range revealed characteristic PVP-induced bathochromic shifts. The presented data point out the potential of PVP as carrier system for amphiphilic derivatives of chlorin e6. The capacity of PVP to monomerize xCE aggregates may enhance their efficiency as possible photosensitizers in PDT.