bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations of aerosol optical properties during the extreme solar event in January 2005
Authors: Mironova I. A. , Desorgher L. , Usoskin I. G. , Flückiger E. O. , Bütikofer R.
Published: September 2008

We present the results of analysis of the aerosol optical depth variations for January 2005 when an extreme solar energetic particle event occurred leading to a greatly enhanced flux of energetic particles penetrating into the atmosphere. An increase of the concentration of sulfate or nitrate aerosol was found on the second day after the solar energetic particle event in the south magnetic pole region with the maximum penetration of anisotropic solar cosmic rays. This suggests that an enhanced flux of solar energetic particles can lead to notable changes in the chemical and physical properties of the polar troposphere. A statistical test confirms that the observed change of the aerosol index is significant and is unlikely to be related to a spatial or temporal independent fluctuation of the aerosol content. Thus, the results of the present work provide evidence of a direct influence of cosmic rays on physical‐chemical properties of the atmosphere.
Ionospheric electric field variations during a geomagnetic storm simulated by a coupled magnetosphere ionosphere thermosphere (CMIT) model
Authors: Wang Wenbin , Lei Jiuhou , Burns Alan G. , Wiltberger Michael , Richmond Arthur D. , Solomon Stanley C. , Killeen Timothy L. , Talaat Elsayed R. , Anderson David N.
Published: September 2008

A coupled magnetosphere ionosphere thermosphere (CMIT 2.0) model has been developed. It is capable of self‐consistently calculating global ionospheric electric fields that include the imposed magnetospheric convection field, neutral wind dynamo and penetration electric fields. The CMIT 2.0 simulated ionospheric F2 region ion vertical drift velocities at the magnetic equator were compared with those measured by ground‐based instruments during the April 2–5, 2004, storm. CMIT 2.0 captured the temporal variations seen in the measurements during both the quiet and active periods. These temporal variations corresponded mainly to the variations in the high latitude electric fields driven by changes in solar wind conditions. CMIT 2.0, however, overestimated the magnitudes of the variations of the vertical drifts. In addition, CMIT 2.0 simulated the observed pre‐reversal enhancement well. This enhancement was driven mostly by the neutral wind dynamo.
High latitude peaks in Mercury's sodium exosphere: Spectral signature using THEMIS solar telescope
Authors: Leblanc F. , Doressoundiram A. , Schneider N. , Mangano V. , López Ariste A. , Lemen C. , Gelly B. , Barbieri C. , Cremonese G.
Published: September 2008

We present the first combined intensity and temperature maps of sodium in Mercury's exosphere, made possible by the use of the THEMIS solar telescope on Tenerife in the Canary Islands. The intensity maps clearly show high‐latitude peaks, and temperatures inferred from spectral line widths suggest that these regions are either slightly hotter than the rest of the exosphere or much smaller than observed. These brighter, warmer regions are also observed, for the first time, to appear within few Earth hours which strongly suggest that they are produced by solar wind sputtering. This highly capable instrument obtained these data during daylight, highlighting the unique potential for THEMIS to undertake continuous multi‐hour and multi‐day datasets in conjunction with the MESSENGER mission to Mercury.
Equatorial plasma bubbles with enhanced ion and electron temperatures
Authors: Park Jaeheung , Min Kyoung Wook , Kim Vitaly P. , Kil Hyosub , Su Shin‐Yi , Chao Chi Kuang , Lee Jae‐Jin
Published: September 2008

While the ion and electron temperatures inside equatorial plasma bubbles (EPBs) are normally lower than those in an ambient plasma, bubbles with enhanced temperatures (BETs) are found occasionally in the topside ionosphere. Here we report the characteristics of BETs identified from observations of the first Republic of China Satellite (ROCSAT‐1), the first Korea Multi‐purpose Satellite (KOMPSAT‐1), and the Defense Meteorological Satellite Program (DMSP) F15 during the solar maximum period between 2000 and 2001. The oxygen ion fraction inside the BETs, which was no lower than that of the ambient ionosphere, was similar to the case of ordinary low‐temperature EPBs. These observations indicate that the BETs and low‐temperature EPBs detected on the topside were produced by the upward drift of low‐density plasma from lower altitudes. The feature that distinguishes BETs from normal EPBs is the occurrence of an unusually fast poleward field‐aligned plasma flow relative to the ambient plasma. The BETs occurred preferentially around geomagnetic latitudes of 10° in the summer hemisphere, where the ambient ion and electron temperatures are lower than those in the conjugate winter hemisphere. The occurrence of BETs did not show any notable dependence on geomagnetic activities. The characteristics of the BETs suggest that the BETs were produced by adiabatic plasma heating associated with a fast poleward oxygen ion transport along magnetic flux tubes.
Upper tropospheric humidity and cirrus geometrical and optical thickness: Relationships inferred from 1 year of collocated AIRS and CALIPSO data
Authors: Lamquin N. , Stubenrauch C. J. , Pelon J.
Published: September 2008

Profiles of relative humidity with respect to ice (RHice) determined from spaceborne passive remote sensing suffer a lack of vertical and spatial resolutions. RHice distributions show dry biases compared to in situ observations because geometrically thin moist layers are integrated within coarser vertical resolutions, a direct effect being the underestimation of ice supersaturation (RHice > 100%) occurrence. Collocated data from the Atmospheric Infrared Sounder (AIRS) and the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) provide the opportunity to investigate relationships between RHice and geometrical thickness and optical depth of high clouds near the tropopause. “Apparent” optical depths are derived for single‐layer high clouds from CALIPSO. By comparing these “apparent” optical depths to cloud infrared emissivities derived from AIRS the multiple scattering contribution is estimated and the optical depths are corrected. Mean RHice increases with cloud geometrical thickness but remains low compared to 100% except for very vertically extended clouds. Optically thicker clouds show on average larger geometrical thickness and larger relative humidity than optically thinner clouds. However, for a comparable geometrical thickness, optically thinner clouds are on average slightly more humid. This study concludes that cloud geometrical thickness has a greater influence than cloud optical depth on RHice integrated within a coarse vertical resolution. Limitations of AIRS humidity observations regarding the detection of ice supersaturation are discussed.
Mutational analysis of the neurexin/neuroligin complex reveals essential and regulatory components
Authors: Reissner Carsten , Klose Martin , Fairless Richard , Missler Markus
Published: September 2008

Neurexins are cell-surface molecules that bind neuroligins to form a heterophilic, Ca
2+
-dependent complex at central synapses. This transsynaptic complex is required for efficient neurotransmission and is involved in the formation of synaptic contacts. In addition, both molecules have been identified as candidate genes for autism. Here we performed mutagenesis experiments to probe for essential components of the neurexin/neuroligin binding interface at the single-amino acid level. We found that in neurexins the contact area is sharply delineated and consists of hydrophobic residues of the LNS domain that surround a Ca
2+
binding pocket. Point mutations that changed electrostatic and shape properties leave Ca
2+
coordination intact but completely inhibit neuroligin binding, whereas alternative splicing in α- and β-neurexins and in neuroligins has a weaker effect on complex formation. In neuroligins, the contact area appears less distinct because exchange of a more distant aspartate completely abolished binding to neurexin but many mutations of predicted interface residues had no strong effect on binding. Together with calculations of energy terms for presumed interface hot spots that complement and extend our mutagenesis and recent crystal structure data, this study presents a comprehensive structural basis for the complex formation of neurexins and neuroligins and their transsynaptic signaling between neurons.
A search for conserved sequences in coding regions reveals that the
let-7
microRNA targets Dicer within its coding sequence
Authors: Forman Joshua J. , Legesse-Miller Aster , Coller Hilary A.
Published: September 2008

Recognition sites for microRNAs (miRNAs) have been reported to be located in the 3′ untranslated regions of transcripts. In a computational screen for highly conserved motifs within coding regions, we found an excess of sequences conserved at the nucleotide level within coding regions in the human genome, the highest scoring of which are enriched for miRNA target sequences. To validate our results, we experimentally demonstrated that the
let-7
miRNA directly targets the miRNA-processing enzyme Dicer within its coding sequence, thus establishing a mechanism for a miRNA/Dicer autoregulatory negative feedback loop. We also found computational evidence to suggest that miRNA target sites in coding regions and 3′ UTRs may differ in mechanism. This work demonstrates that miRNAs can directly target transcripts within their coding region in animals, and it suggests that a complete search for the regulatory targets of miRNAs should be expanded to include genes with recognition sites within their coding regions. As more genomes are sequenced, the methodological approach that we used for identifying motifs with high sequence conservation will be increasingly valuable for detecting functional sequence motifs within coding regions.
Navigating from hippocampus to parietal cortex
Authors: Whitlock Jonathan R. , Sutherland Robert J. , Witter Menno P. , Moser May-Britt , Moser Edvard I.
Published: September 2008

The navigational system of the mammalian cortex comprises a number of interacting brain regions. Grid cells in the medial entorhinal cortex and place cells in the hippocampus are thought to participate in the formation of a dynamic representation of the animal's current location, and these cells are presumably critical for storing the representation in memory. To traverse the environment, animals must be able to translate coordinate information from spatial maps in the entorhinal cortex and hippocampus into body-centered representations that can be used to direct locomotion. How this is done remains an enigma. We propose that the posterior parietal cortex is critical for this transformation.
A polymicrobial perspective of pulmonary infections exposes an enigmatic pathogen in cystic fibrosis patients
Authors: Sibley Christopher D. , Parkins Michael D. , Rabin Harvey R. , Duan Kangmin , Norgaard Jens C. , Surette Michael G.
Published: September 2008

Lung disease is the leading cause of morbidity and mortality in cystic fibrosis (CF) patients. A modest number of bacterial pathogens have been correlated with pulmonary function decline; however, microbiological and molecular evidence suggests that CF airway infection is polymicrobial. To obtain a more complete assessment of the microbial community composition and dynamics, we undertook a longitudinal study by using culture-independent and microbiological approaches. In the process, we demonstrated that within complex and dynamic communities, the
Streptococcus milleri
group (SMG) can establish chronic pulmonary infections and at the onset of 39% of acute pulmonary exacerbations, SMG is the numerically dominant pathogen. We report the comprehensive polymicrobial community dynamics of a CF lung infection in a clinically relevant context. If a given organism, such as
Pseudomonas aeruginosa
, becomes resistant to antibiotic therapy, an alternative treatment avenue may mediate the desired clinical response by effectively managing the composition of the microbial community.
The genome of
Cyanothece
51142, a unicellular diazotrophic cyanobacterium important in the marine nitrogen cycle
Authors: Welsh Eric A. , Liberton Michelle , Stöckel Jana , Loh Thomas , Elvitigala Thanura , Wang Chunyan , Wollam Aye , Fulton Robert S. , Clifton Sandra W. , Jacobs Jon M. , Aurora Rajeev , Ghosh Bijoy K. , Sherman Louis A. , Smith Richard D. , Wilson Richard K. , Pakrasi Himadri B.
Published: September 2008

Unicellular cyanobacteria have recently been recognized for their contributions to nitrogen fixation in marine environments, a function previously thought to be filled mainly by filamentous cyanobacteria such as
Trichodesmium
. To begin a systems level analysis of the physiology of the unicellular N
2
-fixing microbes, we have sequenced to completion the genome of
Cyanothece
sp. ATCC 51142, the first such organism.
Cyanothece
51142 performs oxygenic photosynthesis and nitrogen fixation, separating these two incompatible processes temporally within the same cell, while concomitantly accumulating metabolic products in inclusion bodies that are later mobilized as part of a robust diurnal cycle. The 5,460,377-bp
Cyanothece
51142 genome has a unique arrangement of one large circular chromosome, four small plasmids, and one linear chromosome, the first report of a linear element in the genome of a photosynthetic bacterium. On the 429,701-bp linear chromosome is a cluster of genes for enzymes involved in pyruvate metabolism, suggesting an important role for the linear chromosome in fermentative processes. The annotation of the genome was significantly aided by simultaneous global proteomic studies of this organism. Compared with other nitrogen-fixing cyanobacteria,
Cyanothece
51142 contains the largest intact contiguous cluster of nitrogen fixation-related genes. We discuss the implications of such an organization on the regulation of nitrogen fixation. The genome sequence provides important information regarding the ability of
Cyanothece
51142 to accomplish metabolic compartmentalization and energy storage, as well as how a unicellular bacterium balances multiple, often incompatible, processes in a single cell.
The crystal structure of MexR from
Pseudomonas aeruginosa
in complex with its antirepressor ArmR
Authors: Wilke Mark S. , Heller Markus , Creagh A. Louise , Haynes Charles A. , McIntosh Lawrence P. , Poole Keith , Strynadka Natalie C. J.
Published: September 2008

The intrinsic antimicrobial resistance of the opportunistic human pathogen
Pseudomonas aeruginosa
is compounded in mutant strains that overexpress multidrug efflux pumps such as the prominent drug-proton antiporter, MexAB-OprM. The primary regulator of the
mexAB-oprM
operon is the MarR family repressor, MexR. An additional repressor, NalC, also regulates
mexAB-oprM
by controlling expression of ArmR, an antirepressor peptide that is hypothesized to prevent the binding of MexR to its cognate DNA operator via an allosteric protein–peptide interaction. To better understand how ArmR modulates MexR, we determined the MexR-binding region of ArmR as its C-terminal 25 residues and solved the crystal structure of MexR in a 2:1 complex with this ArmR fragment at 1.8 Å resolution. This structure reveals that the C-terminal residues of ArmR form a kinked α-helix, which occupies a pseudosymmetrical and largely hydrophobic binding cavity located at the centre of the MexR dimer. Although the ArmR-binding cavity partially overlaps with the small molecule effector-binding sites of other MarR family members, it possesses a larger and more complex binding surface to accommodate the greater size and specific physicochemical properties of a peptide effector. Comparison with the structure of apo-MexR reveals that ArmR stabilizes a dramatic conformational change that is incompatible with DNA-binding. Thus, this work defines the structural mechanism by which ArmR allosterically derepresses MexR-controlled gene expression in
P. aeruginosa
and reveals important insights into the regulation of multidrug resistance.
Isolation of human monoclonal antibodies by mammalian cell display
Authors: Beerli Roger R. , Bauer Monika , Buser Regula B. , Gwerder Myriam , Muntwiler Simone , Maurer Patrik , Saudan Philippe , Bachmann Martin F.
Published: September 2008

Due to their low immunogenicity in patients, humanized or fully human mAbs are becoming increasingly important for the treatment of a growing number of diseases, including cancer, infections, and immune disorders. Here, we describe a technology allowing for the rapid isolation of fully human mAbs. In contrast to previously described methods, B cells specific for an antigen of interest are directly isolated from peripheral blood mononuclear cells (PBMC) of human donors. Recombinant, antigen-specific single-chain Fv (scFv) libraries are generated from this pool of B cells and screened by mammalian cell surface display by using a Sindbis virus expression system. This method allows isolating antigen-specific antibodies by a single round of FACS. The variable regions (VRs) of the heavy chains (HCs) and light chains (LCs) are isolated from positive clones and recombinant fully human antibodies produced as whole IgG or Fab fragments. In this manner, several hypermutated high-affinity antibodies binding the Qβ virus like particle (VLP), a model viral antigen, as well as antibodies specific for nicotine were isolated. All antibodies showed high expression levels in cell culture. The human nicotine-specific mAbs were validated preclinically in a mouse model. Thus, the technology presented here allows for rapid isolation of high-affinity, fully human antibodies with therapeutic potential from human volunteers.
The stem rust resistance gene
Rpg5
encodes a protein with nucleotide-binding-site, leucine-rich, and protein kinase domains
Authors: Brueggeman R. , Druka A. , Nirmala J. , Cavileer T. , Drader T. , Rostoks N. , Mirlohi A. , Bennypaul H. , Gill U. , Kudrna D. , Whitelaw C. , Kilian A. , Han F. , Sun Y. , Gill K. , Steffenson B. , Kleinhofs A.
Published: September 2008

We isolated the barley stem rust resistance genes
Rpg5
and
rpg4
by map-based cloning. These genes are colocalized on a 70-kb genomic region that was delimited by recombination. The
Rpg5
gene consists of an unusual structure encoding three typical plant disease resistance protein domains: nucleotide-binding site, leucine-rich repeat, and serine threonine protein kinase. The predicted RPG5 protein has two putative transmembrane sites possibly involved in membrane binding. The gene is expressed at low but detectable levels. Posttranscriptional gene silencing using VIGS resulted in a compatible reaction with a normally incompatible stem rust pathogen. Allele sequencing also validated the candidate
Rpg5
gene. Allele and recombinant sequencing suggested that the probable
rpg4
gene encoded an actin depolymerizing factor-like protein. Involvement of actin depolymerizing factor genes in nonhost resistance has been documented, but discovery of their role in gene-for-gene interaction would be novel and needs to be further substantiated.
Modeling the chemotactic response of
Escherichia coli
to time-varying stimuli
Authors: Tu Yuhai , Shimizu Thomas S. , Berg Howard C.
Published: September 2008

In their natural environment, cells need to extract useful information from complex temporal signals that vary over a wide range of intensities and time scales. Here, we study how such signals are processed by
Escherichia coli
during chemotaxis by developing a general theoretical model based on receptor adaptation and receptor–receptor cooperativity. Measured responses to various monotonic, oscillatory, and impulsive stimuli are all explained consistently by the underlying adaptation kinetics within this model. For exponential ramp signals, an analytical solution is discovered that reveals a remarkable connection between the dependence of kinase activity on the exponential ramp rate and the receptor methylation rate function. For exponentiated sine-wave signals, spectral analysis shows that the chemotaxis pathway acts as a lowpass filter for the derivative of the signal with the cutoff frequency determined by an intrinsic adaptation time scale. For large step stimuli, we find that the recovery time is determined by the constant maximum methylation rate, which provides a natural explanation for the observed recovery time additivity. Our model provides a quantitative system-level description of the chemotaxis signaling pathway and can be used to predict
E. coli
chemotaxis responses to arbitrary temporal signals. This model of the receptor system reveals the molecular origin of Weber's law in bacterial chemotaxis. We further identify additional constraints required to account for the related observation that the output of this pathway is constant under exponential ramp stimuli, a feature that we call “logarithmic tracking.”
Non-cell-autonomous control of vascular stem cell fate by a CLE peptide/receptor system
Authors: Hirakawa Yuki , Shinohara Hidefumi , Kondo Yuki , Inoue Asuka , Nakanomyo Ikuko , Ogawa Mari , Sawa Shinichiro , Ohashi-Ito Kyoko , Matsubayashi Yoshikatsu , Fukuda Hiroo
Published: September 2008

Land plants evolved a long-distance transport system of water and nutrients composed of the xylem and phloem, both of which are generated from the procambium- and cambium-comprising vascular stem cells. However, little is known about the molecular mechanism of cell communication governing xylem–phloem patterning. Here, we show that a dodecapeptide (HEVHypSGHypNPISN; Hyp, 4-hydroxyproline), TDIF (tracheary element differentiation inhibitory factor), is secreted from the phloem and suppresses the differentiation of vascular stem cells into xylem cells through a leucine-rich repeat receptor-like kinase (LRR-RLK). TDIF binds
in vitro
specifically to the LRR-RLK, designated TDR (putative TDIF receptor), whose expression is restricted to procambial cells. However, the combined analysis of TDIF with a specific antibody and the expression profiles of the promoters of two genes encoding TDIF revealed that TDIF is synthesized mainly in, and secreted from, the phloem and its neighboring cells. The observation that TDIF is capable of promoting proliferation of procambial cells while suppressing xylem differentiation suggests that this small peptide functions as a phloem-derived, non-cell-autonomous signal that controls stem cell fate in the procambium. Our results indicate that we have discovered a cell communication system governing phloem–xylem cross-talk.
Formalizing creole sound change
Authors: Russell Eric
Published: September 2008

This article examines sound change in French Lexifier Creoles and the neutralization of contrast involving the feature [round]; secondary concerns include the nature of diachronically related inputs, base richness and decreolization. Phonological restructuring is described in an Optimality Theoretic grammar distinguishing between perceptual, declarative and procedural strata. Base richness holds only at the declarative stratum, as input to the perceptual and procedural strata are constrained by experience and feature licensing, respectively. Explanation of phonological restructuring centers on the perception grammar, where constraints refer to the parsing of experiential input. In the incipient creole, neutralization of contrast predicated by [round] is initially attributed to substrate grammatical transfer, reflecting first language attenuation. The possibility of creole-specific learning or attenuation to second language contrasts is also addressed and shown to lead to distinct output scenarios, depending upon the reranking of constraints under each stratum. Crucially, reranking at either the declarative or procedural strata is dependent upon learning at the perceptual stratum; rankings that do not mirror those of either the lexifier or substrate lead to output variability, the frequency of which is hypothesized to frame the eventual stabilization of representations.
How universal is wanting?
Authors: Khanina Olesya
Published: September 2008

The paper reports on a cross-linguistic survey of translational equivalents of the Standard Average European concept of wanting. It is conducted on a variety sample of 73 languages, each of which was checked for morphosyntactic and semantic properties of its regular means for expressing wanting, i.e. desideratives. Desideratives are shown to typically have other meanings in addition to ‘want’, an array of modal and mental-emotive senses. I suggest that the combination of these meanings with ‘want’ can insightfully be analyzed as a macrofunction, each language making its own decision about the set of situations in which its desideratives can be used. The often-claimed status of WANT as an alleged universal semantic prime is thus seriously called into question by the evidence from languages which always express wanting together with some other situations.
Lexicon and syntax from an emic viewpoint
Authors: Reesink Ger P.
Published: September 2008

Each language has its own limited inventory of constructions from which speakers have to choose when they want to communicate their conceptualizations. This paper discusses a highly productive complex figure construction (Croft 2001:326) in the Papuan language Moi, which requires a number of different translations in English. In both SVO and SOV Papuan languages perceived events are normally expressed in coordinating complex figure constructions, but can appear in figure-ground constructions when pragmatically marked. To capture the genius of a language, interlinear and free translations in descriptive grammars should signal the language-specific links between form and meaning. The conclusion discusses to what extent and under what conditions cross-linguistic comparison of emic constructions is possible.
Seabirds as indicators of the marine environment
Authors: Parsons Matt , Mitchell Ian , Butler Adam , Ratcliffe Norman , Frederiksen Morten , Foster Simon , Reid James B.
Published: September 2008

Parsons, M., Mitchell, I., Butler, A., Ratcliffe, N., Frederiksen, M., Foster, S., and Reid, J. B. 2008. Seabirds as indicators of the marine environment. – ICES Journal of Marine Science, 65: 1520–1526. We report on the development of seabird indicators that support the Scottish Biodiversity Strategy. The application of high-quality monitoring data on breeding abundance and productivity in Scotland was explored in three ways: as indicators of seabird status in its own right, as indicators of the “health” of the marine environment, and as indicators of the food supply of vertebrate predators. Data on breeding productivity of seabirds, which responds more immediately to environmental variation than adult abundance, provided a novel supplement to indicators based solely on abundance trends. Grouping of species according to ecological guilds provided indicators of change in particular aspects of the marine environment. The role of seabird indicators in relation to policy frameworks is discussed, with a look to further developments at the UK and regional scales.
Quality indicators for the prevention and management of cardiovascular disease in primary care in nine European countries
Authors: Campbell Stephen M. , Ludt Sabine , Lieshout Jan Van , Boffin Nicole , Wensing Michel , Petek Davorina , Grol Richard , Roland Martin O.
Published: September 2008

Background

With free movement of labour in Europe, European guidelines on cardiovascular care and the enlargement of the European Union to include countries with disparate health care systems, it is important to develop common quality standards for cardiovascular prevention and risk management across Europe.

Methods

Panels from nine European countries (Austria, Belgium, Finland, France, Germany, Netherlands, Slovenia, United Kingdom and Switzerland) developed quality indicators for the prevention and management of cardiovascular disease in primary care. A two-stage modified Delphi process was used to identify indicators that were judged valid for necessary care.

Results

Forty-four out of 202 indicators (22%) were rated as valid. These focused predominantly on secondary prevention and management of established cardiovascular disease and diabetes. Less agreement on indicators of preventive care or on indicators for the management of hypertension and hypercholesterolemia in patients without established disease was observed. Although 85% of the 202 potential indicators assessed were rated valid by at least one panel, lack of consensus among panels meant that the set that could be agreed upon among all panels was much smaller.

Conclusion

Indicators for the management of established cardiovascular disease have been developed, which can be used to measure the quality of cardiovascular care across a wide range of countries. Less agreement on how the quality of preventive care should be assessed was observed, probably caused by differences in health systems, culture and attitudes to prevention.
Is the MacNew quality of life questionnaire a useful diagnostic and evaluation instrument for cardiac rehabilitation?
Authors: Maes Stan , De Gucht Véronique , Goud Rick , Hellemans Irene , Peek Niels
Published: September 2008

Purpose

The MacNew health-related quality of life questionnaire is internationally used as a standard for psychosocial assessment in many cardiac rehabilitation centres. This study investigates its discriminating capacity between diagnostic disease categories, sex and age at entry (T1) and at the end (T2) of cardiac rehabilitation as well as the responsiveness of the MacNew during this period.

Method

Data were used from 6749 cardiac rehabilitation patients at T1 and 1654 at T2.

Results

Results show that the global MacNew as well as the three (physical, emotional, social) subscales have high internal consistencies, and differentiate well and in the expected direction at T1 between diagnostic groups (heart surgery, myocardial infarction with and without percutaneous coronary intervention, stable angina with and without percutaneous coronary intervention, implantable cardioverter defibrillator, and heart failure patients), sex and age. The MacNew also proves to be an adequate evaluation instrument for cardiac rehabilitation, as all scales are responsive enough to capture changes from T1 to T2. At T2, however, the MacNew seems to lose some of its discriminating power, partly because of ceiling effects.

Conclusion

It is suggested to complement the use of the MacNew both at T1 and T2 with a brief anxiety and depression measure, which is valid and responsive for different groups of cardiac rehabilitation patients.
Lipid-lowering treatment for all could substantially reduce the burden of macrovascular complications of diabetes patients in the Netherlands
Authors: Jacobs-van der Bruggen Monique A.M. , Engelfriet Peter M. , Hoogenveen Rudolf T. , van Baal Pieter H.M. , Struijs Jeroen N. , Verschuren Wilhelmina M.M. , Smit Henriette A. , Baan Caroline A.
Published: September 2008

Background

We aimed to quantify the potential health benefits of increased use of lipid-lowering treatment (LLT), according to current guidelines, for the Dutch diabetes population.

Design

Simulation study.

Methods

We compared the long-term health outcomes for a scenario in which all diabetes patients received LLT to those in a ‘current practice’ scenario, in which 28% received LLT. The model reflected the Dutch diabetes population 40–80 years of age, in 2003. Sensitivity analyses were performed, using more conservative assumptions.

Results

Over the lifetime, LLT for all diabetes patients reduced the expected cumulative incidences of coronary heart disease (CHD) and stroke by, respectively, 6 and 9%. Average life expectancy of Dutch diabetes patients would increase by 0.33 years, ranging from 0.14 years for patients aged 70–79 years, to 0.84 years for patients aged 40–49 years at the start of the simulation. Life-long treatment for patients aged 50–59 contributed most to the life years gained (55 000 out of 146 000). With reduced effectiveness of LLT and fewer patients starting LLT, the cumulative incidences of both CHD and stroke would decrease by approximately 2%. The number needed to treat to prevent one incident case of cardiovascular disease over lifetime was 20 for CHD and 44 for stroke.

Conclusion

This simulation study shows that increased use of LLT can substantially reduce the expected future burden of CHD and stroke in the Dutch diabetes population.
Interaction between income and education in predicting long-term survival after acute myocardial infarction
Authors: Gerber Yariv , Goldbourt Uri , Drory Yaacov ,   for the Israel Study Group on First Acute Myocardial Infarction
Published: September 2008

Background

Population-based data on the impact of socioeconomic status (SES) on long-term survival after myocardial infarction (Ml) are lacking. We evaluated the association of income and education with all-cause mortality and cardiac mortality post-MI and assessed income-by-education interaction.

Design

Prospective cohort study.

Methods

Between February 1992 and February 1993, 1521 consecutive patients aged 65 years or less (19% women) discharged from all hospitals in central Israel after incident acute MI were enrolled and followed up through December 2005. Data on SES indicators, cardiovascular risk factors, MI characteristics and severity, comorbidities, and acute treatment were assessed at baseline.

Results

Low SES, as defined by income and education, was associated with older age, female sex, and higher prevalence of risk factors and comorbidities. Further, low SES patients presented with more severe disease and received fewer cardiac procedures and medications. During follow-up, 427 patients died. Income and education strongly interacted ( P = 0.003). The hazard ratio for death associated with income (below average vs. average/above average) was considerably higher for less educated (≤12 years) patients [2.64, 95% confidence interval (CI): 1.92–3.63] than for more educated (≥12 years) patients (1.53, 95% CI: 1.02–2.29). Adjustment for various prognostic indicators attenuated these estimates, yet excess risk persisted for the less educated group (hazard ratio = 1.58, 95% CI: 1.13–2.21). Similar patterns were noted for cardiac mortality.

Conclusion

Among patients with incident MI, low SES is related to higher risk profile and poorer treatment. Low income is associated with a large increase in mortality risk when accompanied by low education, suggesting a double jeopardy phenomenon.
Trimetazidine potentiates the effects of exercise training in patients with ischemic cardiomyopathy referred for cardiac rehabilitation
Authors: Belardinelli Romualdo , Lacalaprice Francesca , Faccenda Ernesto , Volpe Loretta
Published: September 2008

Background

Patients referred for cardiac rehabilitation may take advantage from combining trimetazidine (TMZ) with exercise training (ET), as both treatments produce similar effects in the cardiovascular system. It is, however, unknown whether the combination of TMZ with ET may determine greater improvements in functional capacity and endothelial function than ET alone.

Design

A randomized longitudinal controlled study.

Methods

We studied 116 patients (97 men and 19 women, mean age 58 ± 9 years) with ischemic heart disease and left ventricular dysfunction who were referred for cardiac rehabilitation. Coronary risk factors were present in 82 patients (diabetes in 28 patients). Patients were randomized into three matched groups. A group (TMZ+ training, TT, n = 30) received TMZ at doses of 20 mg three times daily orally for 8 weeks in addition to standard medications and underwent a supervised program of ET at 60% of oxygen uptake at peak, three times a week for 8 weeks. A group (exercise, E, n = 30) completed the ET program without receiving TMZ. A control group (C, n = 26) was neither exercised nor received TMZ. A fourth group (TMZ, n = 30) receiving TMZ 20 mg three times daily for 8 weeks was also studied. On study entry and at 8 weeks all patients underwent echocardiography, cardiopulmonary exercise testing, and vasomotor reactivity of the brachial artery.

Results

Oxygen uptake at peak was significantly increased in the TT (25%), TMZ (15.1%), and E group (15.3%) (P≤0.001 TT vs. C; P≤0.05 vs. TMZ and E). Left ventricular ejection fraction was also improved in TT (18.4%), TMZ (15.7%), and E (12.9%) (P≤0.001 TT vs. C; P≤0.05 vs. TMZ and E), as a result of reduction in end-systolic volume. The endothelium-dependent dilation was similarly improved (P< 0.001 TMZ vs. C; P<0.05 vs. TMZ and E). The most significant improvements were observed in the subgroup TT with multiple risk factors.

Conclusion

The addition of TMZ to ET determined greater improvements in functional capacity, left ventricular ejection fraction, and endothelium-dependent dilation than TMZ or ET given alone. No differences between improvements after TMZ and E as compared with controls were observed.
Estimation of cardiovascular risk: a comparison between the Framingham and the SCORE model in people under 60 years of age
Authors: Scheltens Tjarda , Verschuren W.M. Monique , Boshuizen Hendriek C. , Hoes Arno W. , Zuithoff Nicolaas P. , Bots Michiel L. , Grobbee Diederick E.
Published: September 2008

Background

The Framingham Heart Study risk model has been used in the majority of cardiovascular risk management guidelines. Recently, a new model based on the SCORE system has been proposed. We compared both risk models with regard to their ability to predict cardiovascular mortality in the Netherlands.

Design

Cohort study.

Methods

In a Dutch cohort study of 39 719 persons, three properties of the risk models were investigated: discriminating ability (ranking persons in order of risks, expressed in area under the curve); calibrating ability (prediction of events compared with actual events expressed in goodness of fit); and the number of persons assigned to treatment according to the guideline.

Results

The discriminative ability of both models was similar: the area under the curve of Framingham was 0.86 and of SCORE 0.85. Calibration of both functions was inadequate. The goodness of fit of the SCORE model was 35 and of the Framingham model 64, whereas a goodness of fit less than 20 is considered acceptable. Using the Dutch guideline treatment threshold of 10% mortality risk, the SCORE risk function assigned 0.4% of the population to drug treatment where the Framingham function assigned 0.7%.

Conclusion

The findings of this study show that both the SCORE and the Framingham model function have a good discriminative ability but are insufficient in predicting absolute risks. SCORE assigned fewer participants to treatment than Framingham. If a new risk model is implemented in treatment guidelines, comparison with the model in use and evaluation of calibrating features is needed.
Long-term prognostic factors of young patients (≤ 35 years) having acute myocardial infarction: the detrimental role of continuation of smoking
Authors: Rallidis Loukianos S. , Lekakis John , Panagiotakos Demosthenes , Fountoulaki Katerina , Komporozos Christoforos , Apostolou Thomas , Rizos loannis , Kremastinos Dimitrios T.
Published: September 2008

Background

There are few and conflicting data regarding the prognostic role of continued smoking in very young survivors of acute myocardial infraction (AMI) after the event.

Design

We conducted a prospective study to evaluate the impact of smoking habits on long-term outcome in individuals who sustained AMI at the age of ≤ 35 years.

Methods

We recruited 147 consecutive patients who had survived their first AMI at the age of ≤ 35 years. Patients were followed up for up to 10 years. Clinical end points were: readmission for acute coronary syndrome, cardiac death or coronary revascularization because of clinical deterioration.

Results

The most prevalent risk factor at presentation was smoking (94.8%). Follow-up data were obtained by 135 patients (32 ± 3 yeas old, 115 men). During follow-up 75 (55.6%) patients reported continuation of smoking. Forty-four (32.6%) patients presented cardiac events (three cardiac deaths, 30 acute coronary syndromes, and 11 revascularizations). Multivariate data analysis showed that persistence of smoking (relative risk = 2.35, 95% confidence interval 1.5–5.25, P = 0.03) and ejection fraction at presentation (relative risk = 0.95, 95% confidence interval 0.91–0.98, P= 0.008) were the only significant predictors of cardiac events after adjusting for various confounding factors. In addition, continuation of smoking was the most significant predictor of cardiac events during follow-up in our sample (i.e. had the lowest log-likelihood ratio as compared with ejection fraction or other covariates).

Conclusion

Persistence of smoking is the most powerful predictor for the recurrence of cardiac events in patients with premature AMI.
Vital exhaustion in coronary heart disease: the impact of socioeconomic status
Authors: Skodova Zuzana , Nagyova Iveta , Rosenberger Jaroslav , van Dijk Jitse P. , Middel Berrie , Vargova Helena , Sudzinova Adriana , Studencan Martin , Reijneveld Sijmen A.
Published: September 2008

Background

Vital exhaustion has been shown to be a significant risk factor contributing to coronary heart disease, as well as a predictor of a worse prognosis among coronary patients. Socioeconomic differences in vital exhaustion may be part of the causal mechanism in the health and mortality inequalities connected with socioeconomic disadvantage. Our aim was to explore socioeconomic inequalities in vital exhaustion among coronary patients.

Methods

We included 362 patients (32% women, mean age 56 ± 7.3 years) who were referred for coronary angiography. The Maastricht interview for vital exhaustion was conducted with each patient. Level of income and education were used as indicators of socioeconomic status. Functional status was assessed with the NYHA (dyspnoe symptoms) and CCS (chest pain) scales.

Results

Logistic regression showed significant socioeconomic inequalities in vital exhaustion among patients. Participants with low and middle income and education had a higher probability of being exhausted in comparison with patients with high income and education [odds ratio (95% confidence interval): 13.31 (4.67–37.94) and 2.10 (1.19–3.64), respectively]. Associations remained statistically significant after controlling for the effect of functional status and seriousness of disease. Socioeconomic differences were more salient among men than among women.

Conclusion

Low education and income seem to be strongly associated with higher vital exhaustion among patients; a significant factor contributing to worse prognosis and lower quality of life among patients with coronary heart disease.
Marital status and risk of out-of-hospital sudden cardiac arrest in the population
Authors: Empana Jean-Philippe , Jouven Xavier , Lemaitre Rozen , Sotoodehnia Nona , Rea Tom , Raghunathan Tom , Simon Gregory , Siscovick David
Published: September 2008

Background

We have recently reported on the association between clinical depression and out-of-hospital sudden cardiac arrest (SCA). In this study, we extend our research on the contribution of psychosocial characteristics to SCA, by examining the association between marital status and out-of-hospital SCA.

Design

A large case-control study of risk factors for incident SCA including 2119 cases and 4042-matched controls.

Methods

Participants were enrollees of a health maintenance organization (USA). Cases experienced SCA between 1980 and 1994 (mean age of 67 years). Controls were a stratified random sample of enrollees, with the strata defined by age, sex, earlier heart disease, and calendar year. The marital status at the time of the SCA or a comparable index date for controls was assessed using ambulatory care medical records. Conditional logistic regression was used to estimate odds ratio and its 95% confidence interval.

Results

Cases were more likely to be unmarried than the controls (30.2% vs. 21.0%), defined as being separated or divorced (10.0% vs. 7.0%), single (5.0% vs. 3.6%) or widowed (15.2% vs. 10.4%). Unmarried participants had a higher risk of SCA (odds ratio: 1.53; 95% confidence interval: 1.33–1.76), after adjustment for SCA risk factors. Consistent findings were observed according to sex, older age (>70 years), earlier coronary heart disease and the presence of clinical depression. Those who were both unmarried and clinically depressed had the highest risk of SCA.

Conclusion

These data support an association between marital status and SCA.
Symptoms of fatigue and depression in ischemic heart disease are driven by personality characteristics rather than disease stage: a comparison of CAD and CHF patients
Authors: Smith Otto R.F. , Pedersen Susanne S. , Van Domburg Ron T. , Denollet Johan
Published: September 2008

Background

Symptoms of fatigue and depression are prevalent across stages of ischemic heart disease (IHD). We examined (i) the effect of both the IHD stage and type-D personality on fatigue and depressive symptoms at 12-month follow-up, and (ii) whether the effect of type-D personality on these symptoms is moderated by IHD stage.

Methods

Two different samples of patients were included to represent IHD stage: 401 percutaneous coronary intervention patients (early-stage IHD) and 105 ischemic chronic heart failure patients (end-stage IHD) completed the DS14 Type-D Scale at baseline. Logistic regression analysis was used to examine the impact of IHD stage and type-D personality on fatigue and depression at follow-up.

Results

Disease stage was neither associated with symptoms of fatigue ( P = 0.99) nor depression ( P = 0.29) at 12 months. In contrast, type-D personality was shown to predict both symptoms of fatigue [odds ratio (OR) = 2.96; 95% confidence interval (CI): 1.92–4.58, P < 0.001] and depression (OR = 4.91; 95% CI: 3.16–7.65, P < 0.001) at follow-up; the effect of type-D personality on these symptoms was not moderated by disease stage. In multivariable analysis, type-D remained a significant predictor of symptoms of fatigue (OR = 3.14; 95% CI: 1.98–4.99, P < 0.001) and depression (OR = 5.90; 95% CI: 3.60–9.67, P < 0.001), also after controlling for symptom levels at baseline.

Conclusion

Type-D personality but not disease stage predicted symptoms of fatigue and depression at 12-month follow-up.
The Need for Standardization of Methods for Worldwide Infant Hearing Screening: A Systematic Review
Authors: Olusanya Bolajoko O. , Somefun Abayomi O. , Swanepoel De Wet
Published: September 2008

No uniform case definition presently exists for infant hearing screening programs worldwide especially for minimal hearing loss (HL). This article systematically reviewed the current practices in developing countries for programs aimed at early detection of “disabling” congenital and early‐onset HL and found significant variations which undermine comparability of key findings in the reported studies. Implications for the exclusion of minimal HL are explored within the context of the International Classification of Functioning, Disability and Health (ICF) of the World Health Organization and its adapted version for children and youth (ICF‐CY). A revised World Health Organization classification that accounts for all categories of HL based on ICF‐CY may provide a suitable framework for improved uniformity in reporting standards.