Crystal-Induced Podocytopathy Producing Collapsing Focal Segmental Glomerulosclerosis in Monoclonal Gammopathy of Renal Significance: A Case Report

Glomeruloesclerosis focal y segmentaria; Queratopatía cristalina; PodocitopatíaGlomeruloesclerosi focal i segmentària; Queratopatia cristal·lina; PodocitopatiaFocal and segmental glomerulosclerosis; Crystalline keratopathy; PodocytopathyMonoclonal gammopathy–associated crystalline podocytopathy causing collapsing focal segmental glomerulosclerosis (FSGS) is very rare and has been associated with pamidronate therapy. We present the case of a 53-year-old man with vision loss secondary to corneal crystals deposition, nephrotic-range proteinuria, and reduced glomerular filtration rate without associated comorbid conditions. Two kidney biopsies were initially reported as primary FSGS but the patient did not respond to high-dose corticosteroid immunosuppression therapy. Re-review of biopsies with additional electron microscopy analysis revealed crystalline inclusions in podocytes leading to collapsing FSGS. Subsequent workup revealed an immunoglobulin G κ serum monoclonal protein. Bone marrow biopsy revealed 5% κ-restricted plasma cells with cytoplasmic crystalline inclusions. To our knowledge, this is the first case of monoclonal gammopathy of clinical significance manifesting as crystalline podocytopathy leading to collapsing FSGS and keratopathy leading to vision loss. Crystalline podocytopathy should be considered in the differential diagnosis of collapsing glomerulopathy, and careful ultrastructural examination of the kidney biopsy specimen is crucial to establish this diagnosis.The authors declare that they have no relevant financial interests

Nonlocalized modulation of periodic reaction diffusion waves: The Whitham equation

In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized modulation plus a localized perturbation. Here, we determine time-asymptotic behavior under such perturbations, showing that solutions consist to leading order of a modulation whose parameter evolution is governed by an associated Whitham averaged equation

Modeling the Longitudinal Asymmetry in Sunspot Emergence -- the Role of the Wilson Depression

The distributions of sunspot longitude at first appearance and at disappearance display an east-west asymmetry that results from a reduction in visibility as one moves from disk centre to the limb. To first order, this is explicable in terms of simple geometrical foreshortening. However, the centre-to-limb visibility variation is much larger than that predicted by foreshortening. Sunspot visibility is also known to be affected by the Wilson effect: the apparent dish shape of the sunspot photosphere caused by the temperature-dependent variation of the geometrical position of the tau=1 layer. In this article we investigate the role of the Wilson effect on the sunspot appearance distributions, deducing a mean depth for the umbral tau=1 layer of 500 to 1500 km. This is based on the comparison of observations of sunspot longitude distribution and Monte Carlo simulations of sunspot appearance using different models for spot growth rate, growth time and depth of Wilson depression.Comment: 18 pages, 10 figures, in press (Solar Physics

Evaluation of flow after transcatheter aortic valve replacement in patients with low-flow aortic stenosis : a secondary analysis of the PARTNER randomized clinical trial

Importance: Low-flow (LF) severe aortic stenosis (AS) is an independent predictor of mortality in patients undergoing aortic valve replacement (AVR). Little is known about improvement in flow after AVR and its effects on survival. Objective: To determine whether higher flow (left-ventricular stroke volume index [LVSVI]) after transcatheter AVR (TAVR) would indicate better clinical outcomes in this at-risk population. Design, Setting, and Participants: A substudy analysis of data from the Placement of Aortic Transcatheter Valves (PARTNER) randomized clinical trial and continued-access registry was conducted. A total of 984 participants with evaluable echocardiograms and baseline LF AS (LVSVI =35 mL/m2) were included. The trial was conducted at 26 sites in the United States and Canada. Patients were stratified after TAVR into tertiles by discharge LVSVI status (severe low flow [SLF], moderate low flow [MLF], and normal flow [(NF]). The present study was conducted from May 11, 2007, to January 9, 2012, with data analysis performed from April 25, 2014, to January 21, 2016. Main Outcomes and Measures: The primary end point was all-cause mortality at 1 year. Results: Baseline characteristics of 984 patients with LF AS included mean (SD) age, 84 (7) years; 582 (59.1%) men; mean Society of Thoracic Surgeons (STS) score, 11.4% (4.0%); and mean LVSVI, 27.6 (5.0) mL/m2. The discharge LVSVI values by group were SLF, 23.1 (3.5) mL/m2; MLF, 31.7 (2.2) mL/m2; and NF, 43.1 (7.0). All-cause mortality at 1 year was SLF, 26.5%; MLF, 20.1%; and NF, 19.6% (P¿=¿.045). Mean LVSVI normalized by 6 months in the MLF (35.9 [9.3] mL/m2) and NF (38.8 [11.1] mL/m2) groups, but remained low in the SLF group at 6 months and 1 year (31.4 [8.4] and 33.0 [8.3] mL/m2], respectively) (P¿<¿.001 for all groups). Reported as multivariate hazard ratio, mortality at 1 year was higher in the SLF group compared with the other groups (1.61; 95% CI, 1.17-2.23; P¿=¿.004). In addition to SLF, sex (1.59; 95% CI, 1.18-2.13; P¿=¿.002), presence of atrial fibrillation (1.41; 95% CI, 1.06-1.87; P¿=¿.02), STS score (1.03; 95% CI, 1.01-1.06; P¿=¿.02), presence of moderate or severe mitral regurgitation at discharge (1.65; 95% CI, 1.21-2.26; P¿=¿.001), pre-TAVR mean transvalvular gradient (0.98; 95% CI, 0.97-0.99; P¿=¿.004), and effective orifice area index (1.87; 95% CI, 1.09-3.19; P¿=¿.02) were independent predictors of 1-year mortality.CONCLUSIONS AND RELEVANCE: Severe LF at discharge is associated with an increased risk of mortality following TAVR in patients with severe AS and preexisting LF. The identification of remedial causes of persistent LF after TAVR may represent an opportunity to improve the outcome of these patients

Echocardiographic assessment of pulmonary hypertension: a guideline protocol from the British Society of Echocardiography.

Pulmonary hypertension is defined as a mean arterial pressure of ≥25 mmHg as confirmed on right heart catheterisation. Traditionally, the pulmonary arterial systolic pressure has been estimated on echo by utilising the simplified Bernoulli equation from the peak tricuspid regurgitant velocity and adding this to an estimate of right atrial pressure. Previous studies have demonstrated a correlation between this estimate of pulmonary arterial systolic pressure and that obtained from invasive measurement across a cohort of patients. However, for an individual patient significant overestimation and underestimation can occur and the levels of agreement between the two is poor. Recent guidance has suggested that echocardiographic assessment of pulmonary hypertension should be limited to determining the probability of pulmonary hypertension being present rather than estimating the pulmonary artery pressure. In those patients in whom the presence of pulmonary hypertension requires confirmation, this should be done with right heart catheterisation when indicated. This guideline protocol from the British Society of Echocardiography aims to outline a practical approach to assessing the probability of pulmonary hypertension using echocardiography and should be used in conjunction with the previously published minimum dataset for a standard transthoracic echocardiogram

Intradural Spinal Cord Stimulation: Performance Modeling of a New Modality

Introduction: Intradural spinal cord stimulation (SCS) may offer significant therapeutic benefits for those with intractable axial and extremity pain, visceral pain, spasticity, autonomic dysfunction and related disorders. A novel intradural electrical stimulation device, limited by the boundaries of the thecal sac, CSF and spinal cord was developed to test this hypothesis. In order to optimize device function, we have explored finite element modeling (FEM).Methods: COMSOL®Multiphysics Electrical Currents was used to solve for fields and currents over a geometric model of a spinal cord segment. Cathodic and anodic currents are applied to the center and tips of the T-cross component of the electrode array to shape the stimulation field and constrain charge-balanced cathodic pulses to the target area.Results: Currents from the electrode sites can move the effective stimulation zone horizontally across the cord by a linear step method, which can be diversified considerably to gain greater depth of penetration relative to standard epidural SCS. It is also possible to prevent spread of the target area with no off-target action potential.Conclusion: Finite element modeling of a T-shaped intradural spinal cord stimulator predicts significant gains in field depth and current shaping that are beyond the reach of epidural stimulators. Future studies with in vivo models will investigate how this approach should first be tested in humans

The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations

The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 sq. deg. region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.Comment: Accepted for publication in The Astronomical Journal (66 pages, 13 figures); typos correcte

Dose dependent effect of statins on postoperative atrial fibrillation after cardiac surgery among patients treated with beta blockers

<p>Abstract</p> <p>Background</p> <p>Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown.</p> <p>Methods</p> <p>We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively).</p> <p>Results</p> <p>Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages.</p> <p>Conclusion</p> <p>Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages</p

Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

Community Preferences for the Allocation &Donation of Organs - The PAraDOx Study

<p>Abstract</p> <p>Background</p> <p>Transplantation is the treatment of choice for people with severe organ failure. However, demand substantially exceeds supply of suitable organs; consequently many people wait months, or years to receive an organ. Reasons for the chronic shortage of deceased organ donations are unclear; there appears to be no lack of 'in principle' public support for organ donation.</p> <p>Methods/Design</p> <p>The PAraDOx Study examines community preferences for organ donation policy in Australia. The aims are to 1) determine which factors influence decisions by individuals to offer their organs for donation and 2) determine the criteria by which the community deems the allocation of donor organs to be fair and equitable. Qualitative and quantitative methods will be used to assess community preferences for organ donation and allocation.</p> <p>Focus group participants from the general community, aged between 18-80, will be purposively sampled to ensure a variety of cultural backgrounds and views on organ donation. Each focus group will include a ranking exercise using a modified nominal group technique. Focus groups of organ recipients, their families, and individuals on a transplant waiting list will also be conducted.</p> <p>Using the qualitative work, a discrete choice study will be designed to quantitatively assess community preferences. Discrete choice methods are based on the premise that goods and services can be described in terms of a number of separate attributes. Respondents are presented with a series of choices where levels of attributes are varied, and a mathematical function is estimated to describe numerically the value respondents attach to different options. Two community surveys will be conducted in approximately 1000 respondents each to assess community preferences for organ donation and allocation. A mixed logit model will be used; model results will be expressed as parameter estimates (β) and the odds of choosing one option over an alternative. Trade-offs between attributes will also be calculated.</p> <p>Discussion</p> <p>By providing a better understanding of current community preferences in relation to organ donation and allocation, the PAraDOx study will highlight options for firstly, increasing the rate of organ donation and secondly, allow for more transparent and equitable policies in relation to organ allocation.</p