25 research outputs found
Glucagonoma-induced acute heart failure
Neuroendocrine tumours (NETs) represent a broad spectrum of tumours, of which the serotonin-producing carcinoid is the most common and has been shown to cause right ventricular heart failure. However, an association between heart failure and NETs other than carcinoid has not been established so far. In this case report, we describe a 51-year-old patient with a glucagon-producing NET of the pancreas who developed acute heart failure and even cardiogenic shock despite therapy. Heart failure eventually regressed after initialising i.v. treatment with the somatostatin analogue octreotide. Chromogranin A as a tumour marker was shown to be significantly elevated, and it decreased with clinical improvement of the patient. The effects of long-time stimulation of glucagon on the myocardium have not been studied yet; however, sarcoplasmic reticulum calcium leak can be discussed as a possible mechanism for glucagon-induced heart failure
Recurrent early filter clotting during continuous veno-venous hemodialysis with regional citrate anticoagulation is linked to systemic thrombin generation and heparin induced thrombocytopenia type II: a retrospective analysis
OBJECTIVE: Regional citrate anticoagulation (RCA) for continuous renal replacement therapy (CRRT) is widely used and leads to an excellent clottingfree filter survival. Despite strict adherence to protocols, in some cases recurrent early filter-clotting occurs. The aim of this observational study was to evaluate the underlying causes and the efficacy of interventions in patients with early recurrent filter-clotting during RCA. METHODS: In a retrospective analysis of a cohort of 1183 patients treated with RCA-CRRT we detected 12 patients with early filter-clotting unrelated to protocol violation or any obvious technical or medical reason. RESULTS: All patients were systemically anticoagulated with low molecular weight or unfractionated heparin for at least 24h before initiation of Continuous Veno-Venous Hemodialysis with RCA (RCA-CVVHD). During RCA, all postfilter ionized calcium concentrations were in the target range (mean 0.33±0.05 mmol/L). At the time of the first clotting event, thrombocyte counts were 168±66/ nL. After the clotting events, the systemic anticoagulation was switched to argatroban in all patients. With systemic anticoagulation using argatroban filter lifetime of RCA-CVVHD increased significantly (p<0.001) and clotting-events decreased from 0.61 to 0.10 per 24h. All patients were tested for HIT and 5/12 (42%) had a positive test for hep-PF4-antibodies. Application of argatroban significantly reduced early filter-clotting both in HIT-positive patients as well as in HIT-negative patients. At the time of the first clotting event, no patient had clinical signs of thrombosis or thromboembolism. However, during follow up a thromboembolic event occurred in three patients. CONCLUSION: In patients with recurrent early filter-clotting despite strict adherence to the citrate protocol undetected HIT or other causes of thrombin activation may be present. Therefore, patients with recurrent early filter clotting in RCA-CVVHD should be screened for HIT or other conditions that may activate thrombin. A significant improvement of filter run-time can be achieved by systemic administration of a thrombin inhibitor both in patients with and without HIT
Detecting the human fingerprint in the summer 2022 westernâcentral European soil drought
In the 2022 summer, westernâcentral Europe and several other regions in the northern extratropics experienced substantial soil moisture deficits in the wake of precipitation shortages and elevated temperatures. Much of Europe has not witnessed a more severe soil drought since at least the mid-20th century, raising the question whether this is a manifestation of our warming climate. Here, we employ a well-established statistical approach to attribute the low 2022 summer soil moisture to human-induced climate change using observation-driven soil moisture estimates and climate models. We find that in westernâcentral Europe, a JuneâAugust root zone soil moisture drought such as in 2022 is expected to occur once in 20 years in the present climate but would have occurred only about once per century during preindustrial times. The entire northern extratropics show an even stronger global warming imprint with a 20-fold soil drought probability increase or higher, but we note that the underlying uncertainty is large. Reasons are manifold but include the lack of direct soil moisture observations at the required spatiotemporal scales, the limitations of remotely sensed estimates, and the resulting need to simulate soil moisture with land surface models driven by meteorological data. Nevertheless, observation-based products indicate long-term declining summer soil moisture for both regions, and this tendency is likely fueled by regional warming, while no clear trends emerge for precipitation. Finally, our climate model analysis suggests that under 2ââC global warming, 2022-like soil drought conditions would become twice as likely for westernâcentral Europe compared to today and would take place nearly every year across the northern extratropics
Baryons: What, When and Where?
We review the current state of empirical knowledge of the total budget of
baryonic matter in the Universe as observed since the epoch of reionization.
Our summary examines on three milestone redshifts since the reionization of H
in the IGM, z = 3, 1, and 0, with emphasis on the endpoints. We review the
observational techniques used to discover and characterize the phases of
baryons. In the spirit of the meeting, the level is aimed at a diverse and
non-expert audience and additional attention is given to describe how space
missions expected to launch within the next decade will impact this scientific
field.Comment: Proceedings Review for "Astrophysics in the Next Decade: JWST and
Concurrent Facilities", ed. X. Tielens, 38 pages, 10 color figures. Revised
to address comments from the communit
A Universal Power-law Prescription for Variability from Synthetic Images of Black Hole Accretion Flows
We present a framework for characterizing the spatiotemporal power spectrum of the variability expected from the horizon-scale emission structure around supermassive black holes, and we apply this framework to a library of general relativistic magnetohydrodynamic (GRMHD) simulations and associated general relativistic ray-traced images relevant for Event Horizon Telescope (EHT) observations of Sgr A*. We find that the variability power spectrum is generically a red-noise process in both the temporal and spatial dimensions, with the peak in power occurring on the longest timescales and largest spatial scales. When both the time-averaged source structure and the spatially integrated light-curve variability are removed, the residual power spectrum exhibits a universal broken power-law behavior. On small spatial frequencies, the residual power spectrum rises as the square of the spatial frequency and is proportional to the variance in the centroid of emission. Beyond some peak in variability power, the residual power spectrum falls as that of the time-averaged source structure, which is similar across simulations; this behavior can be naturally explained if the variability arises from a multiplicative random field that has a steeper high-frequency power-law index than that of the time-averaged source structure. We briefly explore the ability of power spectral variability studies to constrain physical parameters relevant for the GRMHD simulations, which can be scaled to provide predictions for black holes in a range of systems in the optically thin regime. We present specific expectations for the behavior of the M87* and Sgr A* accretion flows as observed by the EHT
Hard Single Diffraction in pbarp Collisions at root-s = 630 and 1800 GeV
Using the D0 detector, we have studied events produced in proton-antiproton
collisions that contain large forward regions with very little energy
deposition (``rapidity gaps'') and concurrent jet production at center-of-mass
energies of root-s = 630 and 1800 Gev. The fractions of forward and central jet
events associated with such rapidity gaps are measured and compared to
predictions from Monte Carlo models. For hard diffractive candidate events, we
use the calorimeter to extract the fractional momentum loss of the scattered
protons.Comment: 11 pages 4 figures. submitted to PR
Schwere Azidose: Differenzialdiagnostik und Therapie [Severe acidosis: differential diagnostics and treatment]
The extracellular H(+) ion concentration in the human body is adjusted within close limits to 40âŻÂ±â0.3âŻnmol/l in blood to ensure maintenance of normal cellular and extracellular homeostasis. The carbonic acid-bicarbonate buffer system is the major regulator of acid-base homeostasis and is readily accessible for the clinician through determination of pH, pCO(2) and HCO3(â). Acidosis is primarily a respiratory or metabolic disorder causing acidemia (H(+) >43âŻnmol/l or pH 60âŻnmol/l or pH <7.2) needs to be diagnosed rapidly and treated according to the underlying condition. A systematic approach with simple bedside diagnostic tools helps to characterize the underlying acid-base disorder, to identify the etiology and to initiate the appropriate causal treatment
The Water Planetary Boundary: Interrogation and Revision
The planetary boundaries framework proposes quantified guardrails to human modification of global environmental processes that regulate the stability of the planet and has been considered in sustainability science, governance, and corporate management. However, the planetary boundary for human freshwater use has been critiqued as a singular measure that does not reflect all types of human interference with the complex global water cycle and Earth System. We suggest that the water planetary boundary will be more scientifically robust and more useful in decision-making frameworks if it is redesigned to consider more specifically how climate and living ecosystems respond to changes in the different forms of water on Earth: atmospheric water, frozen water, groundwater, soil moisture, and surface water. This paper provides an ambitious scientific road map to define a new water planetary boundary consisting of sub-boundaries that account for a variety of changes to the water cycle
The Water Planetary Boundary: Interrogation and Revision
The planetary boundaries framework proposes quantified guardrails to human modification of global environmental processes that regulate the stability of the planet and has been considered in sustainability science, governance, and corporate management. However, the planetary boundary for human freshwater use has been critiqued as a singular measure that does not reflect all types of human interference with the complex global water cycle and Earth System. We suggest that the water planetary boundary will be more scientifically robust and more useful in decision-making frameworks if it is redesigned to consider more specifically how climate and living ecosystems respond to changes in the different forms of water on Earth: atmospheric water, frozen water, groundwater, soil moisture, and surface water. This paper provides an ambitious scientific road map to define a new water planetary boundary consisting of sub-boundaries that account for a variety of changes to the water cycle