Reversible atrial fibrillation secondary to a mega-oesophagus

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it increases in prevalence with advancing age to about 5% in people older than 65 years. CASE PRESENTATION: We present a rare case of atrial fibrillation secondary to a mega-oesophagus occurring in an 84-years-old Caucasian woman. The patient had a history of progressive dysphagia and the accumulation of food debris lead to mega-oesophagus. CONCLUSION: The diagnosis was made by barium swallow and electrocardiogram; evacuations of 300 ml of the food debris lead to complete resolution of the arrhythmia. The possible aetiology leading to this AF is discussed

Risk-Targeted Selection of Agricultural Holdings for Post-Epidemic Surveillance: Estimation of Efficiency Gains

Current post-epidemic sero-surveillance uses random selection of animal holdings. A better strategy may be to estimate the benefits gained by sampling each farm and use this to target selection. In this study we estimate the probability of undiscovered infection for sheep farms in Devon after the 2001 foot-and-mouth disease outbreak using the combination of a previously published model of daily infection risk and a simple model of probability of discovery of infection during the outbreak. This allows comparison of the system sensitivity (ability to detect infection in the area) of arbitrary, random sampling compared to risk-targeted selection across a full range of sampling budgets. We show that it is possible to achieve 95% system sensitivity by sampling, on average, 945 farms with random sampling and 184 farms with risk-targeted sampling. We also examine the effect of ordering samples by risk to expedite return to a disease-free status. Risk ordering the sampling process results in detection of positive farms, if present, 15.6 days sooner than with randomly ordered sampling, assuming 50 farms are tested per day

Glaciotectonic deformation associated with the Orient Point–Fishers Island moraine, westernmost Block Island Sound : further evidence of readvance of the Laurentide ice sheet

This paper is not subject to U.S. copyright. The definitive version was published in Geo-Marine Letters 32 (2012): 279-288, doi:10.1007/s00367-012-0296-9.High-resolution seismic-reflection profiles collected across pro-glacial outwash deposits adjacent to the circa 18 ka b.p. Orient Point–Fishers Island end moraine segment in westernmost Block Island Sound reveal extensive deformation. A rhythmic seismic facies indicates the host outwash deposits are composed of fine-grained glaciolacustrine sediments. The deformation is variably brittle and ductile, but predominantly compressive in nature. Brittle deformation includes reverse faults and thrust faults that strike parallel to the moraine, and thrust sheets that extend from beneath the moraine. Ductile deformation includes folded sediments that overlie undisturbed deposits, showing that they are not drape features. Other seismic evidence for compression along the ice front consists of undisturbed glaciolacustrine strata that dip back toward and underneath the moraine, and angular unconformities on the sea floor where deformed sediments extend above the surrounding undisturbed correlative strata. Together, these ice-marginal glaciotectonic features indicate that the Orient Point–Fishers Island moraine marks a significant readvance of the Laurentide ice sheet, consistent with existing knowledge for neighboring coeval moraines, and not simply a stillstand as previously reported.This work was supported by the Connecticut Department of Environmental Protection, and the Atlantic Hydrographic Branch of the National Oceanic and Atmospheric Administration.2013-06-2

The Female Athlete's Heart: Facts and Fallacies.

Purpose of the review For many years, competitive sport has been dominated by men. Recent times have witnessed a significant increase in women participating in elite sports. As most studies investigated male athletes, with few reports on female counterparts, it is crucial to have a better understanding on physiological cardiac adaptation to exercise in female athletes, to distinguish normal phenotypes from potentially fatal cardiac diseases. This review reports on cardiac adaptation to exercise in females. Recent findings Recent studies show that electrical, structural, and functional cardiac changes due to physiological adaptation to exercise differ in male and female athletes. Women tend to exhibit eccentric hypertrophy, and while concentric hypertrophy or concentric remodeling may be a normal finding in male athletes, it should be evaluated carefully in female athletes as it may be a sign of pathology. Although few studies on veteran female athletes are available, women seem to be affected by atrial fibrillation, coronary atherosclerosis, and myocardial fibrosis less than male counterparts. Summary Males and females exhibit many biological, anatomical, and hormonal differences, and cardiac adaptation to exercise is no exception. The increasing participation of women in sports should stimulate the scientific community to develop large, longitudinal studies aimed at a better understanding of cardiac adaptation to exercise in female athletes

The Current Crisis in Emergency Care and the Impact on Disaster Preparedness

<p>Abstract</p> <p>Background</p> <p>The Homeland Security Act (HSA) of 2002 provided for the designation of a critical infrastructure protection program. This ultimately led to the designation of emergency services as a targeted critical infrastructure. In the context of an evolving crisis in hospital-based emergency care, the extent to which federal funding has addressed disaster preparedness will be examined.</p> <p>Discussion</p> <p>After 9/11, federal plans, procedures and benchmarks were mandated to assure a unified, comprehensive disaster response, ranging from local to federal activation of resources. Nevertheless, insufficient federal funding has contributed to a long-standing counter-trend which has eroded emergency medical care. The causes are complex and multifactorial, but they have converged to present a severely overburdened system that regularly exceeds emergency capacity and capabilities. This constant acute overcrowding, felt in communities all across the country, indicates a nation at risk. Federal funding has not sufficiently prioritized the improvements necessary for an emergency care infrastructure that is critical for an all hazards response to disaster and terrorist emergencies.</p> <p>Summary</p> <p>Currently, the nation is unable to meet presidential preparedness mandates for emergency and disaster care. Federal funding strategies must therefore be re-prioritized and targeted in a way that reasonably and consistently follows need.</p

Fatty acid modulation and polyamine block of GluK2 kainate receptors analyzed by scanning mutagenesis

RNA editing of kainate receptor subunits at the Q/R site determines their susceptibility to inhibition by cis-unsaturated fatty acids as well as block by cytoplasmic polyamines. Channels comprised of unedited (Q) subunits are strongly blocked by polyamines, but insensitive to fatty acids, such as arachidonic acid (AA) and docosahexaenoic acid (DHA), whereas homomeric edited (R) channels resist polyamine block but are inhibited by AA and DHA. In the present study, we have analyzed fatty acid modulation of whole-cell currents mediated by homomeric recombinant GluK2 (formerly GluR6) channels with individual residues in the pore-loop, M1 and M3 transmembrane helices replaced by scanning mutagenesis. Our results define three abutting surfaces along the M1, M2, and M3 helices where gain-of-function substitutions render GluK2(Q) channels susceptible to fatty acid inhibition. In addition, we identify four locations in the M3 helix (F611, L614, S618, and T621) at the level of the central cavity where Arg substitution increases relative permeability to chloride and eliminates polyamine block. Remarkably, for two of these positions, L614R and S618R, exposure to fatty acids reduces the apparent chloride permeability and potentiates whole-cell currents ∼5 and 2.5-fold, respectively. Together, our results suggest that AA and DHA alter the orientation of M3 in the open state, depending on contacts at the interface between M1, M2, and M3. Moreover, our results demonstrate the importance of side chains within the central cavity in determining ionic selectivity and block by cytoplasmic polyamines despite the inverted orientation of GluK2 as compared with potassium channels and other pore-loop family members

Medical encounters (including injury and illness) at mass community-based endurance sports events: an international consensus statement on definitions and methods of data recording and reporting

Mass participation endurance sports events are popular but a large number of participants are older and may be at risk of medical complications during events. Medical encounters (defined fully in the statement) include those traditionally considered 'musculoskeletal' (eg, strains) and those due to 'illness' (eg, cardiac, respiratory, endocrine). The rate of sudden death during mass endurance events (running, cycling and triathlon) is between 0.4 and 3.3 per 100 000 entrants. The rate of other serious medical encounters (eg, exertional heat stroke, hyponatraemia) is rarely reported; in runners it can be up to 100 times higher than that of sudden death, that is, between 16 and 155 per 100 000 race entrants. This consensus statement has two goals. It (1) defines terms for injury and illness-related medical encounters, severity and timing of medical encounters, and diagnostic categories of medical encounters, and (2) describes the methods for recording data at mass participation endurance sports events and reporting results to authorities and for publication. This unifying consensus statement will allow data from various events to be compared and aggregated. This will inform athlete/patient management, and thus make endurance events safer

Intraflagellar transport dynein is autoinhibited by trapping of its mechanical and track-binding elements

Cilia are multi-functional organelles that are constructed using intraflagellar transport (IFT) of cargo to and from their tip. It is widely held that the retrograde IFT motor, dynein-2, must be controlled in order to reach the ciliary tip and then unleashed to power the return journey. However, the mechanism is unknown. Here, we systematically define the mechanochemistry of human dynein-2 motors as monomers, dimers, and multi-motor assemblies with kinesin-II. Combining these data with insights from single-particle electron microscopy, we discover that dynein-2 dimers are intrinsically autoinhibited. Inhibition is mediated by trapping dynein-2’s mechanical “linker” and “stalk” domains within a novel motor-motor interface. We find that linker-mediated inhibition enables efficient transport of dynein-2 by kinesin-II in vitro. These results suggest a conserved mechanism for autoregulation among dimeric dyneins, which is exploited as a switch for dynein-2’s recycling activity during IFT

Scratching the surface: Elastic rotations beneath nanoscratch and nanoindentation tests

In this paper, we investigate the residual deformation field in the vicinity of nanoscratch tests using two orientations of a Berkovich tip on an (001) Cu single crystal. We compare the deformation with that from indentation, in an attempt to understand the mechanisms of deformation in tangential sliding. The lattice rotation fields are mapped experimentally using high-resolution electron backscatter diffraction (HR-EBSD) on cross-sections prepared using focused ion beam (FIB). A physically-based crystal plasticity finite element model (CPFEM) is used to simulate the lattice rotation fields, and provide insight into the 3D rotation field surrounding a nano-scratch experiment, as it transitions from an initial static indentation to a steady-state scratch. The CPFEM simulations capture the experimental rotation fields with good fidelity, and show how the rotations about the scratch direction are reversed as the indenter moves away from the initial indentation