bluuebunny/crossref_metadata_2025_split huggingface dataset:
Right bundle branch block and long‐term mortality in patients with acute congestive heart failure
Authors: MUELLER C. , LAULE‐KILIAN K. , KLIMA T. , BREIDTHARDT T. , HOCHHOLZER W. , PERRUCHOUD A. P. , CHRIST M. 
Published: September 2006

Abstract.Objectives.  Risk stratification in acute congestive heart failure (ACHF) is poorly defined. The aim of the present study was to assess the impact of right bundle brunch block (RBBB) on long‐term mortality in patients presenting with ACHF.Methods and results.  The initial 12‐lead electrocardiogram was analysed for RBBB in 192 consecutive patients presenting with ACHF to the emergency department. The primary endpoint was all‐cause mortality during 720‐day follow‐up. This study included an elderly cohort (mean age 74 years) of ACHF patients. RBBB was present in 27 patients (14%). Age, sex, B‐type natriuretic peptide levels and initial management were similar in patients with RBBB when compared with patients without RBBB. However, patients with RBBB more often had pulmonary comorbidity. A total of 84 patients died during follow‐up. Kaplan–Meier analysis revealed that mortality at 720 days was significantly higher in patients with RBBB when compared with patients without RBBB (63% vs. 39%, P = 0.004). In Cox proportional hazard analysis, RBBB was associated with a two‐fold increase in mortality (hazard ratio 2.18, 95% CI 1.26–3.66; P = 0.003). This association persisted after adjustment for age and comorbidity.Conclusions.  RBBB is a powerful predictor of mortality in patients with ACHF. Early identification of this high‐risk group may help to offer tailored treatment in order to improve outcome.
Antipsychotics and risk of first‐time hospitalization for myocardial infarction: a population‐based case–control study
Authors: NAKAGAWA S. , PEDERSEN L. , OLSEN M. L. , MORTENSEN P. B. , SØRENSEN H. T. , JOHNSEN S. P. 
Published: September 2006

Abstract.Background.  Use of antipsychotics has been linked with an adverse cardiovascular risk factor profile and an increased risk of dysrhythmia and sudden cardiac death. However, detailed data on the association between use of antipsychotics and development of atherosclerotic disease are limited.Objective.  To examine risk of hospitalization for myocardial infarction (MI) amongst users of antipsychotics compared with non‐users.Design and subjects.  A population‐based case–control study using data from hospital discharge registries in the counties of North Jutland, Viborg and Aarhus, Denmark, and the Danish Civil Registration System. We identified 21 377 cases of first‐time hospitalization for MI and 106 885 sex‐ and age‐matched non‐MI population controls in the period 1992–2004. All prescriptions for antipsychotics filled prior to the date of admission for MI were retrieved from population‐based prescription databases. We used conditional logistic regression to adjust for a wide range of covariates.Results.  Current users of atypical [adjusted relative risk: 0.98, 95% confidence interval (CI): 0.88–1.09] and typical antipsychotics (adjusted relative risk: 0.99, 95% CI: 0.96–1.03) had no increased overall risk of being admitted to hospital for MI when compared with non‐users of antipsychotics. These findings were consistent in all examined subgroups. Further, we found no association between the cumulative dose of antipsychotics and the risk of hospitalization for MI.Conclusion.  These findings do not support the hypothesis that use of antipsychotics and in particular atypical antipsychotics is associated with increased risk of MI.
A simple diagnostic strategy in hospitalized patients with clinically suspected pulmonary embolism
Authors: KRUIP M. J. H. A. , SÖHNE M. , NIJKEUTER M. , KWAKKEL‐VAN ERP H. M. , TICK L. W. , HALKES S. J. M. , PRINS M. H. , KRAMER M. H. H. , HUISMAN M. V. , BÜLLER H. R. , LEEBEEK F. W. G. ,   on behalf of the Christopher Study Investigators
Published: September 2006

Abstract.Objectives.  Diagnostic strategies in patients with suspected pulmonary embolism have been extensively studied in outpatients; their value in hospitalized patients has not been well established. Our aim was to determine the safety and clinical utility of a simple diagnostic strategy in hospitalized patients with suspected pulmonary embolism.Design.  Prospective management study.Setting.  Twelve teaching hospitals (five academic, seven general hospitals).Subject.  A total of 605 hospitalized patients with clinically suspected pulmonary embolism. All patients completed the study.Interventions.  First the clinical decision rule (CDR)‐score was calculated. An unlikely CDR‐score in combination with a normal D‐dimer excluded pulmonary embolism. All other patients underwent helical computed tomography (CT). CT either diagnosed or excluded pulmonary embolism, in which case anticoagulants were started or withheld. All patients were instructed to report symptoms of venous thrombosis. Objective tests were performed to confirm venous thromboembolism. The primary outcome was the incidence of symptomatic venous thrombosis during 3‐month follow‐up.Results.  The combination of an unlikely CDR‐score and a normal D‐dimer excluded pulmonary embolism in 60 patients (10% of all patients); no venous thromboembolic event occurred during follow‐up (0%; 95% CI 0–6.7%). CT excluded pulmonary embolism in 380 patients; during follow‐up venous thromboembolism occurred in five patients (1.4%; 95% CI 0.4–3.1%).Conclusions.  An unlikely CDR‐score in combination with a normal D‐dimer appears to exclude pulmonary embolism safely in hospitalized patients. Before clinical implementation it is important this safety is confirmed by others. CT testing was obviated in only 10% of patients. CT can safely exclude pulmonary embolism in hospitalized patients.
Population structure within and between subspecies of the Mediterranean triplefin fish Tripterygion delaisi revealed by highly polymorphic microsatellite loci
Authors: CARRERAS‐CARBONELL J. , MACPHERSON E. , PASCUAL M. 
Published: September 2006

AbstractAlthough FST values are widely used to elucidate population relationships, in some cases, when employing highly polymorphic loci, they should be regarded with caution, particularly when subspecies are under consideration. Tripterygion delaisi presents two subspecies that were investigated here, using 10 microsatellite loci. A Bayesian approach allowed us to clearly identify both subspecies as two different evolutionary significant units. However, low FST values were found between subspecies as a consequence of the large number of alleles per locus, while homoplasy could be disregarded as indicated by the standardized genetic distance . Heterozygosity saturation was observed in highly polymorphic loci containing more than 15 alleles, and this threshold was used to define two loci pools. The less variable loci pool revealed higher genetic variance between subspecies, while the more variable pool showed higher genetic variance between populations. Furthermore, higher differentiation was also observed between populations using with the more variable loci. Nonetheless, a more reliable population structure within subspecies was obtained when all loci were included in the analyses. In T. d. xanthosoma, isolation by distance was detected between the eight analysed populations, and six genetically homogeneous clusters were inferred by Bayesian analyses that are in accordance with FST values. The neighbourhood‐size method also indicated rather small dispersal capabilities. In conclusion, in fish with limited adult and larval dispersal capabilities, continuous rocky habitat seems to allow contact between populations and prevent genetic differentiation, while large discontinuities of sand or deep‐water channels seems to reduce gene flow.
Absence of population structure of turbot (Psetta maxima) in the Baltic Sea
Authors: FLORIN ANN‐BRITT , HÖGLUND JACOB 
Published: September 2006

AbstractWe found low, albeit significant, genetic differentiation among turbot (Psetta maxima) in the Baltic Sea but in contrast to earlier findings we found no evidence of isolation by distance. In fact temporal variation among years in one locality exceeded spatial variation among localities. This is an unexpected result since adult turbot are sedentary and eggs are demersal at the salinities occurring in the Baltic. Our findings are most likely explained by the fact that we sampled fish that were born after/during a large influx of water to the Baltic Sea, which may have had the consequence that previously locally and relatively sedentary populations became admixed. These results suggest that populations that colonize relatively variable habitats, like the Baltic, face problems. Any adaptations to local conditions that may build up during stable periods may quickly become eroded when conditions change and/or when populations become admixed. Our results indicate that the ability of turbot to survive and reproduce at the low salinity in the Baltic is more likely due to phenotypic plasticity than a strict genetic adaptation to low salinity.
Dual function of the germinal centre kinase Don3 during mitosis and cytokinesis in Ustilago maydis
Authors: Sandrock Björn , Böhmer Christian , Bölker Michael 
Published: September 2006

SummarySeptum formation is a crucial step of cytokinesis in fungi. In the basidiomycete Ustilago maydis, the germinal centre kinase Don3 triggers initiation of a secondary septum necessary for cell separation after cytokinesis. Here we show that oligomerization of Don3 via a putative coiled‐coil domain is critical for secondary septum formation. Within the Don3 sequence we detected a characteristic C‐terminal sequence motif (T‐motif), which determines the subcellular localization of Don3 but is not required for regulation of cell separation. This motif defines a novel family of fungal protein kinases including Sid1p, an essential component of the septation initiation network (SIN) in Schizosaccharomyces pombe. Using the yeast two‐hybrid system we isolated the Don3‐interacting protein Dip1, which is similar to S. pombe Cdc14p, another member of the SIN. Remarkably, deletion of dip1 did not interfere with cytokinesis in U. maydis, but both dip1 and don3 mutants were affected in nuclear envelope breakdown (NEBD) during mitosis. This phenotype has already been described for mutants, which lack the small GTPase Ras3, the U. maydis homologue of the SIN component Spg1p. We propose that the Don3 kinase exerts a dual function in the regulation of cell separation and NEBD.
The Group B Streptococcus NADH oxidase Nox‐2 is involved in fatty acid biosynthesis during aerobic growth and contributes to virulence
Authors: Yamamoto Yuji , Pargade Vincent , Lamberet Gilles , Gaudu Philippe , Thomas Fabrice , Texereau Joelle , Gruss Alexandra , Trieu‐Cuot Patrick , Poyart Claire 
Published: September 2006

SummaryNumerous Streptococcaceae produce an H2O‐forming NADH oxidase, Nox‐2, which has been generally implicated in aerobic survival. We examined the roles of Nox‐2 in Group B Streptococcus (GBS), a leading agent of neonatal infections. While nox2 inactivation caused an aerobic growth arrest, no improvement was seen by addition of antioxidants to cultures, suggesting that this defect was not due to accumulation of toxic oxygen species. Using several approaches, we show that the observed inability of the nox2 mutant to grow aerobically is mainly due to an underlying defect in fatty acid (FA) biosynthesis: (i) the nox2 aerobic growth defect is fully and rapidly complemented by adding oleic acid to culture medium, and (ii) direct assimilation of this unsaturated FA in both wild type (WT) and nox2 GBS membranes is demonstrated and correlated with mutant growth rescue. We propose that NAD+ depletion in the nox2 mutant results in reduced acetyl‐CoA production, which perturbs FA biosynthesis and hence blocks growth in aerobiosis. The nox2 aerobic growth defect was also complemented when GBS respiration metabolism was activated by exogenous haem and menaquinone. The membrane NADH oxidase activity generated by the functional respiratory chain thus compensates the cytoplasmic NADH oxidase deficiency. The nox2 mutant was attenuated for virulence, as assessed in lung, intraperitoneal and intravenous murine infection models. As the nox2 defect seems only to affect aerobic growth of GBS, its reduced virulence supports the suggestion that aerobic conditions and NADH oxidase activities are relevant to the GBS infection process.
Type IV pili‐dependent gliding motility in the Gram‐positive pathogen Clostridium perfringens and other Clostridia
Authors: Varga John J. , Nguyen Van , O'Brien David K. , Rodgers Katherine , Walker Richard A. , Melville Stephen B. 
Published: September 2006

SummaryBacteria can swim in liquid media by flagellar rotation and can move on surfaces via gliding or twitching motility. One type of gliding motility involves the extension, attachment and retraction of type IV pili (TFP), which pull the bacterium towards the site of attachment. TFP‐dependent gliding motility has been seen in many Gram‐negative bacteria but not in Gram‐positive bacteria. Recently, the genome sequences of three strains of Clostridium perfringens have been completed and we identified gene products involved in producing TFP in each strain. Here we show that C. perfringens produces TFP and moves with an unusual form of gliding motility involving groups of densely packed cells moving away from the edge of a colony in curvilinear flares. Mutations introduced into the pilT and pilC genes of C. perfringens abolished motility and surface localization of TFP. Genes encoding TFP are also found in the genomes of all nine Clostridium species sequenced thus far and we demonstrated that Clostridium beijerinckii can move via gliding motility. It has recently been proposed that the Clostridia are the oldest Eubacterial class and the ubiquity of TFP in this class suggests that a Clostridia‐like ancestor possessed TFP, which evolved into the forms seen in many Gram‐negative species.
Roles for DNA supercoiling and the Fis protein in modulating expression of virulence genes during intracellular growth of Salmonella enterica serovar Typhimurium
Authors: Ó Cróinín Tadhg , Carroll Ronan K. , Kelly Arlene , Dorman Charles J. 
Published: September 2006

SummaryAdaptation of bacterial pathogens to an intracellular environment requires resetting of the expression levels of a wide range of both virulence and housekeeping genes. We investigated the possibility that changes in DNA supercoiling could modulate the expression of genes known to be important in the intracellular growth of the pathogen Salmonella enterica serovar Typhimurium. Our data show that DNA becomes relaxed when Salmonella grows in murine macrophage but not in epithelial cells, indicating that DNA supercoiling plays a role in discrimination between two types of intracellular environment. The ssrA regulatory gene within the SPI‐2 pathogenicity island that is required for survival in macrophage was found to be upregulated by DNA relaxation. This enhancement of expression also required the Fis nucleoid‐associated protein. Manipulating the level of the Fis protein modulated both the level of DNA supercoiling and ssrA transcription. We discuss a model of bacterial intracellular adaptation in which Fis and DNA supercoiling collaborate to fine‐tune virulence gene expression.
Pre‐replication assembly of E. coli replisome components
Authors: Den Blaauwen Tanneke , Aarsman Mirjam E. G. , Wheeler Linda J. , Nanninga Nanne 
Published: September 2006

SummaryThe localization of SeqA, thymidylate synthase, DnaB (helicase) and the DNA polymerase components α and τ, has been studied by immunofluorescence microscopy. The origin has been labelled through GFP‐LacI bound near oriC. SeqA was located in the cell centre for one replication factory (RF) and at 1/4 and 3/4 positions in pre‐divisional cells harbouring two RFs. The transition of central to 1/4 and 3/4 positions of SeqA appeared abrupt. Labelled thymidylate synthetase was found all over the cell, thus not supporting the notion of a dNTP‐synthesizing complex exclusively localized near the RF. More DnaB, α and τ foci were found than expected. We have hypothesized that extra foci arise at pre‐replication assembly sites, where the number of sites equals the number of origins, i.e. the number of future RFs. A reasonable agreement was found between predicted and found foci. In the case of multifork replication the number of foci appeared consistent with the assumption that three RFs are grouped into a higher‐order structure. The RF is probably separate from the foci containing SeqA and the hemi‐methylated SeqA binding sites because these foci did not coincide significantly with DnaB as marker of the RF. Co‐labelling of DnaB and oriC revealed limited colocalization, indicating that DnaB did not yet become associated with oriC at a pre‐replication assembly site. DnaB and τ co‐labelled in the cell centre, though not at presumed pre‐replication assembly sites. By contrast, α and τ co‐labelled consistently suggesting that they are already associated before replication starts.
Unexpected twist: harnessing the energy in positive supercoils to control telomere resolution
Authors: Bankhead Troy , Kobryn Kerri , Chaconas George 
Published: September 2006

SummaryNegative DNA supercoiling is an important conformational property of bacterial DNA that plays a significant role in a wide variety of DNA transactions. In contrast, positive DNA supercoiling is a by‐product of cellular processes that involve helical unwinding or movement of DNA by a fixed translocase, and has generally been considered a necessary evil requiring removal. We now report the first evidence suggesting a physiological role for positive supercoiling; this occurs in telomere resolution in the related Lyme disease and relapsing fever Borrelia spirochetes. Telomere resolution is the process whereby covalently closed hairpin telomeres are generated from replicative intermediates by the telomere resolvase, ResT. We observe a 20‐fold and greater stimulation of the reaction by positive supercoiling, which facilitates formation of a previously unobserved reaction intermediate. Our data suggest the possibility that the free energy of positive supercoiling, a resource with no previously described cellular function, may be harnessed and utilized as a regulator of post‐replication events.
Polymerase chain reaction in comparison with serological tests for early diagnosis of human leptospirosis
Authors: De Abreu Fonseca Claudia , Teixeira de Freitas Vera Lúcia , Caló Romero Eliete , Spinosa Claudia , Arroyo Sanches Maria Carmem , Da Silva Marcos Vinícius , Shikanai‐Yasuda Maria Aparecida 
Published: September 2006

SummaryThe aim of this study was to compare the sensitivity and specificity of polymerase chain reaction (PCR) using two primer pairs and combined with blood culture, immunoglobulin M enzyme‐linked immunosorbent assay (IgM ELISA), microscopic agglutination test (MAT) and slide agglutination test (SAT) in the diagnosis of human leptospirosis. We analysed 124 serum samples: 60 from patients with confirmed leptospirosis, 20 from patients with other diseases and 44 from healthy individuals. Analysing the first serum sample collected during the first 3–8 days of disease, the sensitivities of the four tests MAT, IgM ELISA, SAT and PCR were, respectively, 69.0%, 79.3%, 72.4% and 62%. In subsequent samples, those same sensitivities were, respectively, 95.4%, 100%, 100% and 72.7% in samples collected from days 9 to 14 and 88.9%, 88.9%, 77.8% and 44.4% in those collected from days 15 to 42. The most specific method (at 100%) was PCR and the least specific (at 89.1%) was IgM ELISA. Although we found PCR to be less sensitive than the serological tests over the course of the disease, our data indicate that PCR was the most sensitive in those initial serum samples presenting no specific antibodies detectable by any of the serological methods tested. We also recommend that PCR can be used in combination with serological tests as we found that this improves the sensitivity of the diagnosis of leptospirosis in the first phase of the disease (93.1–96.5%).
Leishmaniasis in Portugal: enzyme polymorphism of Leishmania infantum based on the identification of 213 strains
Authors: Campino L. , Pratlong F. , Abranches P. , Rioux J.‐A. , Santos‐Gomes G. , Alves‐Pires C. , Cortes S. , Ramada J. , Cristovão J. M. , Afonso M. O. , Dedet J. P. 
Published: September 2006

SummaryThis study reports isoenzyme polymorphism of Leishmania strains isolated in different regions of Portugal between 1982 and 2005. A total of 213 strains were obtained from cases of visceral and cutaneous leishmaniasis isolated from immunocompetent patients (adults and children) and immunocompromised adults, as well as from dogs and sandflies. Four zymodemes were identified: MON‐1, MON‐24, MON‐29 and MON‐80. Zymodeme MON‐1 was identified in 96.7% of the strains, predominating in both immunocompetent and immunocompromised human patients, and it was the only zymodeme isolated from dogs. Isoenzyme diversity in HIV‐infected patients was higher than in the immunocompetent group, in which all the strains from visceral leishmaniasis were MON‐1. The domestic dog was confirmed as the reservoir host of zoonotic leishmaniasis in Portugal and Phlebotomus perniciosus and Phlebotomus ariasi as vectors. The overall low enzyme polymorphism observed in the Portuguese foci contrasts with the neighbouring foci in Spain.
Suppression of exposure to malaria vectors by an order of magnitude using microbial larvicides in rural Kenya
Authors: Fillinger Ulrike , Lindsay Steven W. 
Published: September 2006

SummaryObjective  To determine the contribution larviciding could make to reduce the burden of malaria, by conducting a trial of microbial larvicides in a 4.5 km2 area in and around a large village in rural western Kenya.Method  The abundance of immature and adult mosquitoes was monitored for 12 months under baseline conditions. Then microbial larval control was implemented for 28 months. After the intervention, the abundance of immature and adult mosquitoes was monitored for a further 12 months.Results  Of the 419 mosquito larval habitats identified, 336 (80%) originated from human activities. Application of Bacillus thuringiensis var. israelensis and Bacillus sphaericus larvicides reduced the proportion of aquatic habitats containing Anopheles larvae from 51% during non‐intervention periods to 7% during the intervention. The occurrence of late instar Anopheles in habitats was reduced from 39% and 33% in pre‐intervention and post‐intervention periods to 0.6% during intervention. Overall, larviciding reduced Anopheles larval density by 95% and human exposure to bites from adults by 92%. The estimated cost of providing this protection to the human population in the study area was less than US$ 0.90/person/year.Conclusion  Appropriately applied microbial larvicides can substantially and cost‐effectively reduce human exposure to malaria in rural sub‐Saharan Africa.
Effectiveness of handwashing in preventing SARS: a review
Authors: Fung Isaac Chun‐Hai , Cairncross Sandy 
Published: September 2006

SummaryThis review examines the literature, including literature in Chinese, on the effectiveness of handwashing as an intervention against severe acute respiratory syndrome (SARS) transmission. Nine of 10 epidemiological studies reviewed showed that handwashing was protective against SARS when comparing infected cases and non‐infected controls in univariate analysis, but only in three studies was this result statistically significant in multivariate analysis. There is reason to believe that this is because most of the studies were too small. The evidence for the effectiveness of handwashing as a measure against SARS transmission in health care and community settings is suggestive, but not conclusive.