Socioeconomic status and incidence of sudden cardiac arrest

Background:

Low socioeconomic status is associated with poor cardiovascular health. We evaluated the association between socioeconomic status and the incidence of sudden cardiac arrest, a condition that accounts for a substantial proportion of cardiovascular-related deaths, in seven large North American urban populations.

Methods:

Using a population-based registry, we collected data on out-of-hospital sudden cardiac arrests occurring at home or at a residential institution from Apr. 1, 2006, to Mar. 31, 2007. We limited the analysis to cardiac arrests in seven metropolitan areas in the United States (Dallas, Texas; Pittsburgh, Pennsylvania; Portland, Oregon; and Seattle–King County, Washington) and Canada (Ottawa and Toronto, Ontario; and Vancouver, British Columbia). Each incident was linked to a census tract; tracts were classified into quartiles of median household income.

Results:

A total of 9235 sudden cardiac arrests were included in the analysis. For all sites combined, the incidence of sudden cardiac arrestin the lowest socioeconomic quartile was nearly double that in the highest quartile (incidence rate ratio [IRR] 1.9, 95% confidence interval [CI] 1.8–2.0). This disparity was greater among people less than 65 years old (IRR 2.7, 95% CI 2.5–3.0) than among those 65 or older (IRR 1.3, 95% CI 1.2–1.4). After adjustment for study site and for population age structure of each census tract, the disparity across socioeconomic quartiles for all ages combined was greater in the United States (IRR 2.0, 95% CI 1.9–2.2) than in Canada (IRR 1.8, 95% CI 1.6–2.0) (p < 0.001 for interaction).

Interpretation:

The incidence of sudden cardiac arrest at home or at a residential institution was higher in poorer neighbourhoods of the US and Canadian sites studied, although the association was attenuated in Canada. The disparity across socioeconomic quartiles was greatest among people younger than 65. The association between socioeconomic status and incidence of sudden cardiac arrest merits consideration in the development of strategies to improve survival from sudden cardiac arrest, and possibly to identify opportunities for prevention.An estimated 250 000–300 000 sudden cardiac arrests occur each year in the United States,¹ accounting for up to 63% of cardiac-related deaths annually.² Despite advances in resuscitation, more than 95% of people who experience sudden cardiac arrest die,³ and up to 50% of sudden cardiac arrests occur in people who do not have a history of coronary artery disease.⁴Socioeconomic status has been shown to predict many health outcomes, including all-cause mortality,⁵ prevalence of risk factors for cardiovascular disease⁶ and incidence of cardiovascular disease.^7–9 Despite this substantial literature, we found only three studies that examined the potential association between socioeconomic status and sudden cardiac arrest. Although the studies were small and conducted in single communities, each showed that the incidence of sudden cardiac arrest was significantly higher in lower socioeconomic areas.^10–12 The Oregon Sudden Unexplained Death Study (Ore-SUDS) reported a 30%–80% higher incidence of sudden cardiac arrest in poorer neighbourhoods. A stronger association was observed among people less than 65 years old, a group for whom basic health care funding is not guaranteed in the United States.¹¹Low socioeconomic status may be linked to an increased risk of sudden cardiac arrest by a variety of mechanisms related to individual risk factors or health-promoting behaviours or neighbourhood characteristics. Individuals of lower socioeconomic status have been found to have a greater burden of risk factors for cardiovascular disease,¹³ poorer control of established cardiovascular risk factors¹⁴ and longer delays in seeking hospital care for acute myocardial infarction.¹⁵ Numerous studies have also shown that disparities in health outcomes are apparent across the spectrum of socioeconomic status.¹⁶A better understanding of community-level patterns in the distribution of sudden cardiac arrest may identify opportunities for improving survival, such as effective targeting of community training for cardiopulmonary resuscitation and placement of automated external defibrillators in lower-income communities. We tested the hypothesis that disparities in the incidence of sudden cardiac arrest by level of socioeconomic status would be evident in a variety of urban communities in the United States and Canada, and that this association would be most prominent among people less than 65 years old residing in US communities.     

Novel purification method for mammalian seminal plasma phospholipid-binding proteins reveals the presence of a novel member of this family of protein in stallion seminal fluid

A family of bull seminal plasma (BSP) phospholipid-binding proteins (BSP proteins), potentiate heparin- and HDL-induced capacitation. The homologous proteins have been purified from stallion and boar seminal plasma, and detected in low concentrations in other mammalian seminal plasma. In this study, we developed a new isolation method for mammalian seminal plasma choline phospholipid-binding proteins wherein they are present in low concentrations. The method is based on the interaction of this family of proteins with egg yolk low-density lipoprotein fraction (LDF). In order to demonstrate the feasibility of the method, we incubated LDF with alcohol precipitates of bull, boar, and stallion seminal plasma. LDF were re-isolated by ultracentrifugation along with bound proteins. LDF with associated proteins were dialyzed, lyophilized, and delipidated. BSP homologous proteins were finally purified by p-aminophenyl phosphorylcholine (PPC)-agarose and/or gelatin-agarose chromatographies, and analyzed by SDS-PAGE. With this new protocol, phospholipid-binding proteins of bull, boar, and stallion seminal plasma were recovered almost 100%. A new 12 kDa stallion seminal plasma protein of the same family was also isolated and partially sequenced. The radio-immunoassay (RIA) data showed that 10 mg of LDF can bind all BSP proteins present in 120 mg of alcohol precipitated BSP proteins. These results confirm the efficiency of the method and that the LDF step could be used for the isolation of all BSP proteins homologs from different mammalian species.     

A Genome-Wide Scan for Evidence of Selection in a Maize Population Under Long-Term Artificial Selection for Ear Number

A genome-wide scan to detect evidence of selection was conducted in the Golden Glow maize long-term selection population. The population had been subjected to selection for increased number of ears per plant for 30 generations, with an empirically estimated effective population size ranging from 384 to 667 individuals and an increase of more than threefold in the number of ears per plant. Allele frequencies at >1.2 million single-nucleotide polymorphism loci were estimated from pooled whole-genome resequencing data, and F_ST values across sliding windows were employed to assess divergence between the population preselection and the population postselection. Twenty-eight highly divergent regions were identified, with half of these regions providing gene-level resolution on potentially selected variants. Approximately 93% of the divergent regions do not demonstrate a significant decrease in heterozygosity, which suggests that they are not approaching fixation. Also, most regions display a pattern consistent with a soft-sweep model as opposed to a hard-sweep model, suggesting that selection mostly operated on standing genetic variation. For at least 25% of the regions, results suggest that selection operated on variants located outside of currently annotated coding regions. These results provide insights into the underlying genetic effects of long-term artificial selection and identification of putative genetic elements underlying number of ears per plant in maize.     

Genetic parameters for growth, wood density and pulp yield in Eucalyptus globulus

Genetic variation and co-variation among the key pulpwood selection traits for Eucalyptus globulus were estimated for a range of sites in Portugal, with the aim of improving genetic parameters used to predict breeding values and correlated response to selection. The trials comprised clonally replicated full-sib families (eight trials) and unrelated clones (17 trials), and exhibited varying levels of pedigree connectivity. The traits studied were stem diameter at breast height, Pilodyn penetration (an indirect measure of wood basic density) and near infrared reflectance predicted pulp yield. Univariate and multivariate linear mixed models were fitted within and across sites, and estimates of additive genetic, total genetic, environmental and phenotypic variances and covariances were obtained. All traits studied exhibited significant levels of additive genetic variation. The average estimated within-site narrow-sense heritability was 0.19 ± 0.03 for diameter and 0.29 ± 0.03 for Pilodyn penetration, and the pooled estimate for predicted pulp yield was 0.42 ± 0.14. When they could be tested, dominance and epistatic effects were generally not statistically significant, although broad-sense heritability estimates were slightly higher than narrow-sense heritability estimates. Averaged across trials, positive additive (0.64 ± 0.08), total genetic (0.58 ± 0.04), environmental (0.38 ± 0.03) and phenotypic (0.43 ± 0.02) correlation estimates were consistently obtained between diameter and Pilodyn penetration. This data argues for at least some form of pleiotropic relationship between these two traits and that selection for fast growth will adversely affect wood density in this population. Estimates of the across-site genetic correlations for diameter and Pilodyn penetration were high, indicating that the genotype by environment interaction is low across the range of sites tested. This result supports the use of single aggregated selection criteria for growth and wood density across planting environments in Portugal, as opposed to having to select for performance in different environments.     

A SELDI‐TOF MS procedure for the detection,quantitation, and preliminary characterization of low‐molecular‐weight recombinant proteins expressed in transgenic plants

We describe a SELDI‐TOF MS procedure for the rapid detection and quantitation of low‐molecular‐weight recombinant proteins expressed in plants. Transgenic lines of potato (Solanum tuberosum L.) expressing the clinically useful protein bovine aprotinin or the cysteine protease inhibitor corn cystatin II were generated by Agrobacterium tumefaciens‐mediated transformation, and then used as test material for the analyses. Real‐time RT‐PCR amplifications and detection of the recombinant proteins by immunoblotting were first conducted for transformed potato lines accumulating the proteins in different cell compartments. Both proteins were found at varying levels in leaves, depending on their final cellular destination and transgene expression rate. These conclusions drawn from standard immunodetection assays were easily confirmed by SELDI‐TOF MS comparative profiling, after immobilizing the leaf proteins of control and transformed lines on protein biochips for weak cationic exchange. This procedure, carried out in less than 2 h, allows for the rapid comparison of recombinant protein levels in transgenic plant lines. The molecular weight of immobilized proteins can also be determined directly from the MS spectra, thus providing a simple way to assess the structural integrity and homogeneity of recombinant proteins in planta, and to identify the most suitable cellular compartments for their heterologous production.     

Force Control Deficits in Individuals with Parkinson’s Disease,Multiple Systems Atrophy,and Progressive Supranuclear Palsy

Objective

This study examined grip force and cognition in Parkinson’s disease (PD), Parkinsonian variant of multiple system atrophy (MSAp), progressive supranuclear palsy (PSP), and healthy controls. PD is characterized by a slower rate of force increase and decrease and the production of abnormally large grip forces. Early-stage PD has difficulty with the rapid contraction and relaxation of hand muscles required for precision gripping. The first goal was to determine which features of grip force are abnormal in MSAp and PSP. The second goal was to determine whether a single variable or a combination of motor and cognitive measures would distinguish patient groups. Since PSP is more cognitively impaired relative to PD and MSAp, we expected that combining motor and cognitive measures would further distinguish PSP from PD and MSAp.

Methods

We studied 44 participants: 12 PD, 12 MSAp, 8 PSP, and 12 controls. Patients were diagnosed by a movement disorders neurologist and were tested off anti-Parkinsonian medication. Participants completed a visually guided grip force task wherein force pulses were produced for 2 s, followed by 1 s of rest. We also conducted four cognitive tests.

Results

PD, MSAp, and PSP were slower at contracting and relaxing force and produced longer pulse durations compared to controls. PSP produced additional force pulses during the task and were more cognitively impaired relative to other groups. A receiver operator characteristic analysis revealed that the combination of number of pulses and Brief Test of Attention (BTA) discriminated PSP from PD, MSAp, and controls with a high degree of sensitivity and specificity.

Conclusions

Slowness in contracting and relaxing force represent general features of PD, MSAp, and PSP, whereas producing additional force pulses was specific to PSP. Combining motor and cognitive measures provides a robust method for characterizing behavioral features of PSP compared to MSAp and PD.     

Microsatellites for use in Nothofagus cunninghamii (Nothofagaceae) and related species

Nothofagus cunninghamii (myrtle) has a widespread distribution through the temperate rainforest of southeastern Australia with some disjunct populations existing in putative glacial refugia. Polymorphic nuclear markers are required to resolve the biogeographical history of the species and will also be useful for conservation and forestry applications in this and other species of Nothofagus. Fourteen polymorphic microsatellite loci were isolated from N. cunninghamii, with four to 10 alleles amplified in 15 individuals tested. Transferability to other species of Nothofagus was successful, with six loci transferring to all eight other species tested.     

Synthesis of HPr(Ser-P)(His-P) by enzyme I of the phosphoenolpyruvate: sugar phosphotransferase system of Streptococcus salivarius

HPr is a protein of the bacterial phosphoenolpyruvate:sugar phosphotransferase transport system (PTS). In Gram-positive bacteria, HPr can be phosphorylated on Ser(46) by HPr(Ser) kinase/phosphorylase (HPrK/P) and on His(15) by enzyme I (EI) of the PTS. In vitro studies have shown that phosphorylation on one residue greatly inhibits the second phosphorylation. However, streptococci contain significant amounts of HPr(Ser-P)(His approximately P) during exponential growth, and recent studies suggest that phosphorylation of HPr(Ser-P) by EI is involved in the recycling of HPr(Ser-P)(His approximately P). We report in this paper a study on the phosphorylation of Streptococcus salivarius HPr, HPr(Ser-P), and HPr(S46D) by EI. Our results indicate that (i) the specificity constant (k(cat)/K(m)) of EI for HPr(Ser-P) at pH 7.9 was approximately 5000-fold smaller than that observed for HPr, (ii) no metabolic intermediates were able to stimulate HPr(Ser-P) phosphorylation, (iii) the rate of HPr phosphorylation decreased at pHs below 6.5, while that of HPr(Ser-P) increased and was almost 10-fold higher at pH 6.1 than at pH 7.9, (iv) HPr(S46D), a mutated HPr alleged to mimic HPr(Ser-P), was also phosphorylated more efficiently under acidic conditions, and, lastly, (v) phosphorylation of Bacillus subtilis HPr(Ser-P) by B. subtilis EI was also stimulated at acidic pH. Our results suggest that the high levels of HPr(Ser-P)(His approximately P) in streptococci result from the combination of two factors, a high physiological concentration of HPr(Ser-P) and stimulation of HPr(Ser-P) phosphorylation by EI at acidic pH, an intracellular condition that occurs in response to the acidification of the external medium during growth of the culture.