241 research outputs found

    Effect of site of lactate infusion on regional lactate exchange in pigs

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    Background The rate of extra-hepatic lactate production and the route of influx of lactate to the liver may influence both hepatic and extra-hepatic lactate exchange. We assessed the dose-response of hepatic and extra-hepatic lactate exchange during portal and central venous lactate infusion. Methods Eighteen pigs randomly received either portal (n=5) or central venous (n=7) lactate infusion or saline (n=6). Sodium lactate was infused at 33, 66, 99, and 133 ”mol kg−1 min−1 for 20 min each. Systemic and regional abdominal blood flows and plasma lactate were measured at 20 min intervals until 1 h post-infusion, and regional lactate exchange was calculated (area under lactate uptake-time curve). Results Total hepatic lactate uptake [median (95% confidence interval)] during the experimental protocol (140 min) was higher during portal [8198 (5487-12 798) ”mol kg−1] than during central venous lactate infusion [4530 (3903-5514) ”mol kg−1, P<0.05]. At a similar hepatic lactate delivery (∌400 ”mol kg−1 min−1), hepatic lactate uptake [mean and standard deviation (sd)] was higher during portal [118 (sd 55) ”mol kg−1 min−1] than during central venous lactate infusion [44 (12) ”mol kg−1 min−1, P<0.05]. Time courses of arterial lactate concentrations and lactate uptake at other measured regions were similar in both groups. Conclusions Higher hepatic lactate uptake during portal compared with central venous lactate infusion at a similar total hepatic lactate influx underlines the role of portal vein lactate concentration in total hepatic lactate uptake capacity. Arterial lactate concentration does not depend on the site of lactate infusion. At higher arterial lactate concentrations, all regions participated in lactate uptak

    Photodynamische Therapie bei altersbedingter Makuladegeneration am schlechteren und besseren Auge

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    Zusammenfassung: Hintergrund: Die PDT ist die Standardbehandlung vieler Formen der exsudativen bzw. neovaskulĂ€ren Makuladegeneration (AMD). Trotz Therapie fĂ€llt die SehschĂ€rfe hĂ€ufig in den Low-vision-Bereich ab. Die Kosteneffizienz der Therapie am schlechteren Auge wird daher kontrovers diskutiert. Patienten und Methoden: Retrospektive Fallkontrollstudie aller Patienten, welche zwischen September 1999 und November 2004 am UniversitĂ€tsspital ZĂŒrich eine PDT erhalten haben. Die Situation bei PrĂ€sentation und der Verlauf unter Therapie wurden bei ersten (schlechteren) und zweiten (besseren) Augen verglichen. Ergebnisse: In 117/228FĂ€llen (51,3%) war der Visus am behandelten Auge bei PrĂ€sentation besser (oder gleich) als der Visus am Partnerauge. Der Visus vor Behandlung betrug bei den besseren Augen im Mittel 0,58±0,27logMAR [Snellen: 0,26 (0,14-0,49)] und 0,69±0,4logMAR [Snellen 0,20 (0,08-0,51)] bei den schlechteren Augen (p=0,015). Nach Behandlung bestand zwischen den Gruppen weder bezĂŒglich Visus bzw. VisusverĂ€nderung noch bezĂŒglich MembrangrĂ¶ĂŸe bzw. GrĂ¶ĂŸenverĂ€nderung der Membran ein signifikanter Unterschied. Schlussfolgerung: Die Resultate nach PDT sind beim zweiten (bzw. besseren) Auge nicht signifikant besser als beim ersten (bzw. schlechteren) Aug

    Treatment of Branch Retinal Vein Occlusion induced Macular Edema with Bevacizumab

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    BACKGROUND: Branch retinal vein occlusion is a frequent cause of visual loss with currently insufficient treatment options. We evaluate the effect of Bevacizumab (Avastin) treatment in patients with macular edema induced by branch retinal vein occlusion. METHODS: Retrospective analysis of 32 eyes in 32 patients with fluorescein angiography proven branch retinal vein occlusion, macular edema and Bevacizumab treatment. Outcome measures were best corrected visual acuity in logMAR and central retinal thickness in OCT. RESULTS: Visual acuity was significantly better 4 to 6 weeks after Bevacizumab treatment compared to visual acuity prior to treatment (before 0.7 +/- 0.3 and after 0.5 +/- 0.3; mean +/- standard deviation; p < 0.01, paired t-test). Gain in visual acuity was accompanied by a significant decrease in retinal thickness (454 +/- 117 to 305 +/- 129 microm, p < 0.01, paired t-test). Follow up (170, 27 - 418 days; median, range) shows that improvement for both visual acuity and retinal thickness last for several months after Bevacizumab use. CONCLUSION: We present evidence that intravitreal Bevacizumab is an effective and lasting treatment for macular edema after branch retinal vein occlusion

    Constraints from orbital motions around the Earth of the environmental fifth-force hypothesis for the OPERA superluminal neutrino phenomenology

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    It has been recently suggested by Dvali and Vikman that the superluminal neutrino phenomenology of the OPERA experiment may be due to an environmental feature of the Earth, naturally yielding a long-range fifth force of gravitational origin whose coupling with the neutrino is set by the scale M_*, in units of reduced Planck mass. Its characteristic length lambda should not be smaller than one Earth's radius R_e, while its upper bound is expected to be slightly smaller than the Earth-Moon distance (60 R_e). We analytically work out some orbital effects of a Yukawa-type fifth force for a test particle moving in the modified field of a central body. Our results are quite general since they are not restricted to any particular size of lambda; moreover, they are valid for an arbitrary orbital configuration of the particle, i.e. for any value of its eccentricity ee. We find that the dimensionless strength coupling parameter alpha is constrained to |alpha| <= 1 10^-10-4 10^-9 for 1 R_e <= lambda <= 10 R_e by the laser data of the Earth's artificial satellite LAGEOS II, corresponding to M_* >= 4 10^9 -1.6 10^10. The Moon perigee allows to obtain |alpha| <= 3 10^-11 for the Earth-Moon pair in the range 15 R_e <= lambda = 3 10^10 - 4.5 10^10. Our results are neither necessarily limited to the superluminal OPERA scenario nor to the Dvali-Vikman model, in which it is M_* = 10^-6 at lambda = 1 R_e, in contrast with our bounds: they generally extend to any theoretical scenario implying a fifth-force of Yukawa-type.Comment: LaTex2e, 18 pages, 4 figures, 1 table, 81 reference

    Wetscapes : Restoring and maintaining peatland landscapes for sustainable futures

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    Peatlands are among the world's most carbon-dense ecosystems and hotspots of carbon storage. Although peatland drainage causes strong carbon emissions, land subsidence, fires and biodiversity loss, drainage-based agriculture and forestry on peatland is still expanding on a global scale. To maintain and restore their vital carbon sequestration and storage function and to reach the goals of the Paris Agreement, rewetting and restoration of all drained and degraded peatlands is urgently required. However, socio-economic conditions and hydrological constraints hitherto prevent rewetting and restoration on large scale, which calls for rethinking landscape use. We here argue that creating integrated wetscapes (wet peatland landscapes), including nature preserve cores, buffer zones and paludiculture areas (for wet productive land use), will enable sustainable and complementary land-use functions on the landscape level. As such, transforming landscapes into wetscapes presents an inevitable, novel, ecologically and socio-economically sound alternative for drainage-based peatland use

    Rewetting offers rapid climate benefits for tropical and agricultural peatlands but not for forestry‐drained peatlands

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    Peat soils drained for agriculture and forestry are important sources of carbon dioxide and nitrous oxide. Rewetting effectively reduces these emissions. However, rewetting also increases methane emissions from the soil and, on forestry-drained peatlands, decreases the carbon storage of trees. To analyze the effect of peatland rewetting on the climate, we built radiative forcing scenarios for tropical peat soils, temperate and boreal agricultural peat soils, and temperate and boreal forestry-drained peat soils. The effect of tree and wood product carbon storage in boreal forestry-drained peatlands was also estimated as a case study for Finland. Rewetting of tropical peat soils resulted in immediate cooling. In temperate and boreal agricultural peat soils, the warming effect of methane emissions offsets a major part of the cooling for the first decades after rewetting. In temperate and boreal forestry-drained peat soils, the effect of rewetting was mostly warming for the first decades. In addition, the decrease in tree and wood product carbon storage further delayed the onset of the cooling effect for decades. Global rewetting resulted in increasing climate cooling, reaching -70 mW (m(2)Earth)(-1)in 100 years. Tropical peat soils (9.6 million ha) accounted for approximately two thirds and temperate and boreal agricultural peat soils (13.0 million ha) for one third of the cooling. Forestry-drained peat soils (10.6 million ha) had a negligible effect. We conclude that peatland rewetting is beneficial and important for mitigating climate change, but abandoning tree stands may instead be the best option concerning forestry-drained peatlands.Peer reviewe

    Active afforestation of drained peatlands is not a viable option under the EU Nature Restoration Law

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    The EU Nature Restoration Law (NRL) is critical in restoring degraded ecosystems. However, active afforestation of degraded peatlands has been suggested by some as a restoration measure under the NRL. Here, we discuss the current state of scientific evidence on the climate mitigation effects of peatlands under forestry and its limitations, uncertainties and evidence gaps. Based on this discussion we conclude: Afforestation of drained peatlands, while maintaining their drained state, is not equivalent to ecosystem restoration. This approach will not restore the peatland ecosystem's flora, fauna, and functions. There is insufficient evidence to support the long-term climate change mitigation benefits of active afforestation of drained peatlands. Most studies only focus on the short-term gains in standing biomass and rarely explore the full life cycle emissions associated with afforestation of drained peatlands. Thus, it is unclear whether the CO2 sequestration of a forest on drained peatland can offset the carbon loss from the peat over the long term. In some ecosystems, such as abandoned or certain cutaway peatlands, afforestation may provide short-term benefits for climate change mitigation compared to taking no action. However, this approach violates the concept of sustainability by sacrificing the most space-effective carbon store of the terrestrial biosphere, the long-term peat store, for a shorter-term, less space-effective, and more vulnerable carbon store, namely tree biomass. Consequently, active afforestation of drained peatlands is not a viable option for climate mitigation under the EU Nature Restoration Law and might even impede future rewetting/restoration efforts. To restore degraded peatlands, hydrological conditions must first be improved, primarily through rewetting

    Defining a Minimum Set of Standardized Patient-centered Outcome Measures for Macular Degeneration

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    Purpose To define a minimum set of outcome measures for tracking, comparing, and improving macular degeneration care. Design Recommendations from a working group of international experts in macular degeneration outcomes registry development and patient advocates, facilitated by the International Consortium for Health Outcomes Measurement (ICHOM). Methods Modified Delphi technique, supported by structured teleconferences, followed by online surveys to drive consensus decisions. Potential outcomes were identified through literature review of outcomes collected in existing registries and reported in major clinical trials. Outcomes were refined by the working group and selected based on impact on patients, relationship to good clinical care, and feasibility of measurement in routine clinical practice. Results Standardized measurement of the following outcomes is recommended: visual functioning and quality of life (distance visual acuity, mobility and independence, emotional well-being, reading and accessing information); number of treatments; complications of treatment; and disease control. Proposed data collection sources include administrative data, clinical data during routine clinical visits, and patient-reported sources annually. Recording the following clinical characteristics is recommended to enable risk adjustment: age; sex; ethnicity; smoking status; baseline visual acuity in both eyes; type of macular degeneration; presence of geographic atrophy, subretinal fibrosis, or pigment epithelial detachment; previous macular degeneration treatment; ocular comorbidities. Conclusions The recommended minimum outcomes and pragmatic reporting standards should enable standardized, meaningful assessments and comparisons of macular degeneration treatment outcomes. Adoption could accelerate global improvements in standardized data gathering and reporting of patient-centered outcomes. This can facilitate informed decisions by patients and health care providers, plus allow long-term monitoring of aggregate data, ultimately improving understanding of disease progression and treatment responses
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