152 research outputs found
Restricted exchangeable partitions and embedding of associated hierarchies in continuum random trees
We introduce the notion of a restricted exchangeable partition of
. We obtain integral representations, consider associated
fragmentations, embeddings into continuum random trees and convergence to such
limit trees. In particular, we deduce from the general theory developed here a
limit result conjectured previously for Ford's alpha model and its extension,
the alpha-gamma model, where restricted exchangeability arises naturally.Comment: 35 pages, 5 figure
A new family of Markov branching trees: the alpha-gamma model
We introduce a simple tree growth process that gives rise to a new
two-parameter family of discrete fragmentation trees that extends Ford's alpha
model to multifurcating trees and includes the trees obtained by uniform
sampling from Duquesne and Le Gall's stable continuum random tree. We call
these new trees the alpha-gamma trees. In this paper, we obtain their splitting
rules, dislocation measures both in ranked order and in sized-biased order, and
we study their limiting behaviour.Comment: 23 pages, 1 figur
Sudden cardiac death caused by myocarditis in persons aged 1-49 years:a nationwide study of 14â294 deaths in Denmark
Gender differences in sudden cardiac death in the young-a nationwide study
Abstract
Background
Hitherto, sudden cardiac death (SCD) in the young has been described with no distinction between genders. SCD occurs more often in men (SCDm) than women (SCDw), but this disparity is not understood and has not been investigated systematically in a nationwide setting. Our objective was to report gender differences in SCD in the young in a nationwide (Denmark) setting.
Methods
All deaths in persons aged 1\u201335 years nationwide in Denmark between 2000 and 2009 were included. Death certificates and autopsy reports were obtained. The extensive health care registries in Denmark were used to investigate any known disease prior to death. SCDw were compared to SCDm.
Results
During the 10-year study period there were a total of 8756 deaths in 23.7 million person-years. In total, 635 deaths were SCD. SCDw constituted 205 deaths (32%). Women had a higher proportion of witnessed deaths (51 vs. 41%, p \u2009=\u20090.02) and died less often in a public place (16 vs. 26%, p \u2009=\u20090.01). Age at death, ratios of autopsies and sudden unexplained deaths, and comorbidities, did not differ. Causes of SCD were largely comparable between genders. The incidence rate of SCDw was half of that of SCDm (1.8 vs. 3.6 per 100,000 person-years, incidence rate ratio 2.0 (95% CI 1.7\u20132.4), p \u2009<\u20090.01).
Conclusions
Incidence rate ratio of SCDm vs SCDw is 2. Young SCDw and SCDm are equally investigated, have comparable comorbidity, and causes of SCD. SCD due to potentially inherited cardiac diseases is less often in young women and could reflect a protection of female gender
Sudden cardiac death among persons with diabetes aged 1-49 years:a 10-year nationwide study of 14â294 deaths in Denmark
Aims
The aim of this study was to compare nationwide incidence rate (IR) of sudden cardiac death (SCD) in persons aged 1â49 years with and without diabetes mellitus (DM).
Methods and results
The study population consisted of all persons in Denmark aged 1â49 years in 2000â09, which equals 27.1 million person-years. All 14 294 deaths in the 10-year period were included. By using the highly descriptive Danish death certificates, 1698 cases of sudden and unexpected death were identified. Through review of autopsy reports, discharge summaries, and the Danish registries, we identified 1363 cases of SCD. The Danish Register of Medicinal Product Statistics was used to identify persons with type 1 DM and type 2 DM. Among the 14 294 decedents, there were 669 with DM, of which 118 suffered SCD (9% of all SCD), making SCD the leading cause of death among young persons with DM. Among those aged 1â35 years, the IR of SCD-DM was 21.9 per 100 000 person-years compared to 2.6 per 100 000 person-years among persons without DM [IR ratio 8.6, 95% confidence interval (CI) 5.8â28.6]. Within the age range 36â49 years, the IR among persons with DM was 119.8 per 100 000 person-years compared to 19.7 per 100 000 person-years among persons without DM (IR ratio 6.1, 95% CI 4.7â7.8).
Conclusion
We found that young persons with DM aged 1â35 years had >8-fold higher SCD IR compared to young persons without DM. Our study highlights the need for early cardiovascular risk monitoring and assessment in young persons with DM.This work was supported by the Novo Nordisk Foundation, Copenhagen, Denmark [NNFOC140011573]. JS, reciewed salary from the Department of Forensic Medicine, Univiserty of Copenhagen
A Novel SCN5A Mutation in a Patient with Coexistence of Brugada Syndrome Traits and Ischaemic Heart Disease
Brugada syndrome (BrS) is a primary electrical heart disease, which can lead to sudden cardiac death. In older patients with BrS, the disease may coexist with ischaemic heart disease (IHD) and recent studies support a synergistic proarrhythmic effect of the two disease entities. We report a case that illustrates this. The index patient was a middle-aged patient with BrS traits, IHD, and aborted sudden cardiac death. Mutation analysis discovered a novel mutation P468L in the NaV1.5 sodium channel. Surprisingly, voltage-clamp experiments on the wild-type and mutant NaV1.5 channels expressed in HEK cells revealed no functional effect of the mutation.
In a patient like ours, the distinction between IHD and BrS as the cause of an aborted sudden cardiac death is hard to establish and mounting evidence shows that coexistence of the two may have a synergistic proarrhythmic effect
Duration of Resuscitation and Long-Term Outcome After In-Hospital Cardiac Arrest:A Nationwide Observational Study
Sudden unexpected death caused by stroke:A nationwide study among children and young adults in Denmark
Severity of Brugada syndrome disease manifestation and risk of new-onset depression or anxiety:a Danish nationwide study
Whole-genome amplified DNA from stored dried blood spots is reliable in high resolution melting curve and sequencing analysis
<p>Abstract</p> <p>Background</p> <p>The use of dried blood spots (DBS) samples in genomic workup has been limited by the relative low amounts of genomic DNA (gDNA) they contain. It remains to be proven that whole genome amplified DNA (wgaDNA) from stored DBS samples, constitutes a reliable alternative to gDNA.</p> <p>We wanted to compare melting curves and sequencing results from wgaDNA derived from DBS samples with gDNA derived from whole blood.</p> <p>Methods</p> <p>gDNA was extracted from whole blood obtained from 10 patients with lone atrial fibrillation (mean age 22.3 years). From their newborn DBS samples, stored at -24°C, genomic DNA was extracted and whole-genome amplified in triplicates. Using high resolution melting curve analysis and direct sequencing in both wgaDNA and gDNA samples, all coding regions and adjacent intron regions of the genes <it>SCN5A </it>and <it>KCNA5 </it>were investigated.</p> <p>Results</p> <p>Altered melting curves was present in 85 of wgaDNA samples and 81 of gDNA samples. Sequence analysis identified a total of 31 variants in the 10 wgaDNA samples. The same 31 variants were found in the exact same pattern of samples in the gDNA group. There was no false positive or negative sequence variation in the wgaDNA group.</p> <p>Conclusions</p> <p>The use of DNA amplified in triplicates from DBS samples is reliable and can be used both for high resolution curve melting analysis as well as direct sequence analysis. DBS samples therefore can serve as an alternative to whole blood in sequence analysis.</p
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