Consequence Of Volume Expansion Research Articles

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Defining and Measuring Fluid Overload in Hemodialysis Patients.

In the saga of clinical nephrology, fluid overloadappears as one of the most important modifiablerisk factors for mortality in dialysis patients, poten-tially even more fundamental than poor nutrition.The present review article aims at providing opin-ion-based answers to three questions on fluidoverload, namely: (i) fluid overload: Why bother?(ii) what is fluid overload and how can it be mea-sured? (iii) what have we learned from bioimped-ance-based measurements of fluid overload?Fluid Overload: Why Bother?Datasets on hemodialysis patients have evolvedfrom early local registries, through nationwidesurveys (including the United States Renal DataSystem (1)) to international studies (2,3). This gath-ering of information is aimed at improving dialysiscare and, ultimately, cardiovascular disease mortal-ity, which is 10–30 times higher in dialysis patientsthan in the general population (4,5). Among theirprimary risk factors are higher age, presence ofdiabetes, and other comorbidities (6,7), but thesefactors are not modifiable. Traditional, modifiablerisk factors include central vein catheters, an inade-quate dialysis prescription (lower treatment timeand Kt/V), and poor nutrition (8). A previousanalysis of an observational dataset suggested that,of the principal, modifiable risk factors, a serumalbumin <3.5 g/dl (relative risk = 1.38, p < 0.0001)was associated with the highest relative risk ofmortality (9).Fluid overload is another modifiable risk factor.To the best of our knowledge, three analyses havebeen published to date regarding the mortality riskassociated with quantified fluid overload:(i) In a blinded study of 269 patients, those withpredialysis fluid overload surpassing 15% oftheir extracellular volume had an adjusted haz-ard ratio for all-cause mortality of 2.10 (90%CI 1.39–3.18), compared to those with fluidoverload below 15% of their extracellular vol-ume (reference) (10).(ii) In comparison to a positively selected reference pop-ulation comprising 50 “normohydrated” patientsfrom the “long, slow dialysis” center in Tassin/France (11), 35 fluid overloaded patients fromanother unit (an excess of 3.5 1.2 l predialysis,equivalent to 20.2 4.8% of their extracellular vol-ume) had an adjusted hazard ratio for all-causemortality of 3.41 (90% CI 1.62 –7.17) (12).(iii) In a study of 309 patients using a plasma vol-ume monitor, those with rapid plasma refilling(a slope below the median of 1.39% per hour),an indicator of fluid overload, had a hazardratio for mortality of 1.72 (95% CI 1.14–2.58)compared to patients with steeper slopes (13).The results derived from these relatively small threedatasets (10–12) cannot be readily compared withthose obtained from the large observational studiesmentioned before. Nevertheless, hazard ratios formortality between 1.72 and 3.41 are big risks, com-pared with the relative risk of 1.38 associated with aserum albumin concentration of <3.5 g/dl (9). Fluidoverload may thus be the most important modifiablerisk factor for mortality in dialysis patients.What is Fluid Overload/How Can FluidOverload Be Measured?Fluid overload is a widely used medical term withan International Classification of Diseases (ICD)

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Intra-dialytic Hypotension in Conventional Hemodialysis: Unavoidable in Some, but Preventable in Most.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Intra-dialytic Hypotension in Conventional Hemodialysis: Unavoidable in Some, but Preventable in Most.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: The Consequences of Fluid overload in AKI.

Seminars in DialysisVolume 28, Issue 3 p. 247-249 Opinion What are the Consequences of Volume Expansion in Chronic Dialysis Patients? The Consequences of Fluid overload in AKI Ranil Gajanayaka, Ranil Gajanayaka Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorSteven Coca, Corresponding Author Steven Coca Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USAAddress correspondence to: Steven Coca, DO, MS, Division of Nephrology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1243, New York, NY 10029, USA, Tel.: 212-241-6633, or e-mail: [email protected].Search for more papers by this author Ranil Gajanayaka, Ranil Gajanayaka Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorSteven Coca, Corresponding Author Steven Coca Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USAAddress correspondence to: Steven Coca, DO, MS, Division of Nephrology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1243, New York, NY 10029, USA, Tel.: 212-241-6633, or e-mail: [email protected].Search for more papers by this author First published: 09 February 2015 https://doi.org/10.1111/sdi.12352Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume28, Issue3May–June 2015Pages 247-249 RelatedInformation

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Pulmonary Manifestations of Volume Expansion.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Pulmonary Manifestations of Volume Expansion.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Hypertension as a Manifestation of Volume Overload in Hemodialysis Patients.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Hypertension as a Manifestation of Volume Overload in Hemodialysis Patients.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Volume Expansion in Peritoneal Dialysis Patients.

What are the Consequences of Volume Expansion in Chronic Dialysis Patients?: Volume Expansion in Peritoneal Dialysis Patients.

Simulation of E. coli Gene Regulation including Overlapping Cell Cycles, Growth, Division, Time Delays and Noise

Due to the complexity of biological systems, simulation of biological networks is necessary but sometimes complicated. The classic stochastic simulation algorithm (SSA) by Gillespie and its modified versions are widely used to simulate the stochastic dynamics of biochemical reaction systems. However, it has remained a challenge to implement accurate and efficient simulation algorithms for general reaction schemes in growing cells. Here, we present a modeling and simulation tool, called ‘GeneCircuits’, which is specifically developed to simulate gene-regulation in exponentially growing bacterial cells (such as E. coli) with overlapping cell cycles. Our tool integrates three specific features of these cells that are not generally included in SSA tools: 1) the time delay between the regulation and synthesis of proteins that is due to transcription and translation processes; 2) cell cycle-dependent periodic changes of gene dosage; and 3) variations in the propensities of chemical reactions that have time-dependent reaction rates as a consequence of volume expansion and cell division. We give three biologically relevant examples to illustrate the use of our simulation tool in quantitative studies of systems biology and synthetic biology.

LARGE-SCALE EXTREME-ULTRAVIOLET DISTURBANCES ASSOCIATED WITH A LIMB CORONAL MASS EJECTION

We present composite observations of a coronal mass ejection (CME) and the associated large-scale extreme-ultraviolet (EUV) disturbances on 2007 December 31 by the Extreme-ultraviolet Imager (EUVI) and COR1 coronagraph on board the recent Solar Terrestrial Relations Observatory mission. For this limb event, the EUV disturbances exhibit some typical characteristics of EUV Imaging Telescope waves: (1) in the 195 A bandpass, diffuse brightenings are observed propagating oppositely away from the flare site with a velocity of ~260 km s–1, leaving dimmings behind; (2) when the brightenings encounter the boundary of a polar coronal hole, they stop there to form a stationary front. Multi-temperature analysis of the propagating EUV disturbances favors a heating process over a density enhancement in the disturbance region. Furthermore, the EUVI-COR1 composite display shows unambiguously that the propagation of the diffuse brightenings coincides with a large lateral expansion of the CME, which consequently results in a double-loop-structured CME leading edge. Based on these observational facts, we suggest that the wave-like EUV disturbances are a result of magnetic reconfiguration related to the CME liftoff rather than true waves in the corona. Reconnections between the expanding CME magnetic field lines and surrounding quiet-Sun magnetic loops account for the propagating diffuse brightenings; dimmings appear behind them as a consequence of volume expansion. X-ray and radio data provide us with complementary evidence.

Theoretical study of the magnetism within Gd/Mo and Gd/W multilayers

The local-spin-density approximation (LSDA) and generalized-gradient approximation of Perdew, Burke, and Ernzerhof (PBE) are implemented within the framework of the semirelativistic self-consistent tight-binding linear-muffin-tin orbital in the atomic-sphere-approximation scheme. Energy-volume and magnetovolume studies of bulk Gd, Mo, and W are presented. Use of the LSDA in the study of Gd indicates that the antiferromagnetic structure is energetically favorable at the equilibrium lattice parameter which is 3% smaller than the experimental value. Application of the PBE functional predicts the experimentally observed ferromagnetic ground state at an equilibrium lattice parameter close to (+0.5%) the experimental value. Magnetovolume studies of Mo and W predict that, although both these metals possess a nonmagnetic bcc ground state, they will exhibit antiferromagnetic behavior at large volumes regardless of whether the structure of the idealized unit cell is bcc, fcc, or hcp. Magnetic behavior as a consequence of volume expansion is also predicted to occur on the Mo or W sites within Gd/$X (X=\mathrm{M}\mathrm{o},\mathrm{W})$ bilayers. Moreover, for the case of a 5Gd/3Mo multilayer, constructed using the volume parameters of bulk Gd, the magnetic behavior of the Gd and Mo layers is nearly identical to that of the constituent bulk elements at the same volume. We have thus demonstrated that any possible occurrence of a magnetic moment on a Mo or W site within such a multilayer is a direct consequence of volume effects only.