280 research outputs found
Registers of the Swedish total population and their use in medical research
The primary aim of the Swedish national population registration system is to
obtain data that (1) reflect the composition, relationship and identities of the
Swedish population and (2) can be used as the basis for correct decisions and
measures by government and other regulatory authorities. For this purpose, Sweden
has established two population registers: (1) The Population Register, maintained
by the Swedish National Tax Agency ("Folkbokforingsregistret"); and (2) The Total
Population Register (TPR) maintained by the government agency Statistics Sweden
("Registret over totalbefolkningen"). The registers contain data on life events
including birth, death, name change, marital status, family relationships and
migration within Sweden as well as to and from other countries. Updates are
transmitted daily from the Tax Agency to the TPR. In this paper we describe the
two population registers and analyse their strengths and weaknesses. Virtually
100 % of births and deaths, 95 % of immigrations and 91 % of emigrations are
reported to the Population Registers within 30 days and with a higher proportion
over time. The over-coverage of the TPR, which is primarily due to underreported
emigration data, has been estimated at up to 0.5 % of the Swedish population.
Through the personal identity number, assigned to all residents staying at least
1 year in Sweden, data from the TPR can be used for medical research purposes,
including family design studies since each individual can be linked to his or her
parents, siblings and offspring. The TPR also allows for identification of
general population controls, participants in cohort studies, as well as
calculation of follow-up time.NonePublishe
Infant tidal flow–volume parameters and arousal state
This version is distributed under the terms of the Creative Commons Attribution NonCommercial Licence 4.0. For commercial reproduction rights and permissions contact: [email protected]: Infant lung function can be assessed with tidal flow–volume (TFV) loops. While TFV loops can be measured in both awake and sleeping infants, the influence of arousal state in early infancy is not established. The aim of the present study was to determine whether TFV loop parameters in healthy infants differed while awake compared to the sleeping state at 3 months of age.
Methods: From the population-based Scandinavian Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) birth cohort, 91 infants had reproducible TFV loops measured with Exhalyzer® D in both the awake and sleeping state at 3 months of age. The TFV loops were manually selected according to a standardised procedure. The ratio of time to peak tidal expiratory flow (tPTEF) to expiratory time (tE) and the corresponding volume ratio (VPTEF/VE), as well as tidal volume (VT) and respiratory rate were compared using nonparametric tests.
Results: The mean (95% CI) tPTEF/tE was significantly higher while awake compared to the sleeping state: 0.39 (0.37–0.41) versus 0.28 (0.27–0.29); with the corresponding VPTEF/VE of 0.38 (0.36–0.40) versus 0.29 (0.28–0.30). The VT was similar, while the respiratory rate was higher while awake compared to the sleeping state: 53 (51–56) breaths·min−1 versus 38 (36–40) breaths·min−1 .
Conclusion: Higher tPTEF/tE, VPTEF/VE and respiratory rate, but similar VT while awake compared to the sleeping state suggests that separate normative TFV loop values according to arousal state may be required in early infancy.publishedVersio
Aggregation and fibril morphology of the Arctic mutation of Alzheimer's Aβ peptide by CD, TEM, STEM and in situ AFM
Morphology of aggregation intermediates, polymorphism of amyloid fibrils and aggregation kinetics of the "Arctic" mutant of the Alzheimer's amyloid β-peptide, Aβ(1-40)(E22G), in a physiologically relevant Tris buffer (pH 7.4) were thoroughly explored in comparison with the human wild type Alzheimer's amyloid peptide, wt-Aβ(1-40), using both in situ atomic force and electron microscopy, circular dichroism and thioflavin T fluorescence assays. For arc-Aβ(1-40) at the end of the 'lag'-period of fibrillization an abrupt appearance of ∼3nm size 'spherical aggregates' with a homogeneous morphology, was identified. Then, the aggregation proceeds with a rapid growth of amyloid fibrils with a variety of morphologies, while the spherical aggregates eventually disappeared during in situ measurements. Arc-Aβ(1-40) was also shown to form fibrils at much lower concentrations than wt-Aβ(1-40): ≤2.5μM and 12.5μM, respectively. Moreover, at the same concentration, 50μM, the aggregation process proceeds more rapidly for arc-Aβ(1-40): the first amyloid fibrils were observed after c.a. 72h from the onset of incubation as compared to approximately 7days for wt-Aβ(1-40). Amyloid fibrils of arc-Aβ(1-40) exhibit a large variety of polymorphs, at least five, both coiled and non-coiled distinct fibril structures were recognized by AFM, while at least four types of arc-Aβ(1-40) fibrils were identified by TEM and STEM and their mass-per-length statistics were collected suggesting supramolecular structures with two, four and six β-sheet laminae. Our results suggest a pathway of fibrillogenesis for full-length Alzheimer's peptides with small and structurally ordered transient spherical aggregates as on-pathway immediate precursors of amyloid fibrils. © 2012 Elsevier Inc
Reduced cerebrospinal fluid concentration of interleukin-12/23 subunit p40 in patients with cognitive impairment
BACKGROUND: The role of inflammation in Alzheimer’s disease (AD) and other cognitive disorders is unclear. In a well-defined mono-center population, we measured cytokines and chemokines in paired serum and cerebrospinal fluid (CSF) samples. METHODS: Consecutive patients with AD (n = 30), stable mild cognitive impairment (SMCI, n = 11), other dementias (n = 11), and healthy controls (n = 18) were included. None of the subjects was treated with glucocorticoids, cholinesterase inhibitors, or non-steroidal anti-inflammatory drugs. Serum and CSF concentrations of interleukin-6 (IL-6), IL-8, IL-12/23 p40, IL-15, IL-16, vascular endothelial growth factor-A (VEGF-A), and three chemokines were measured using a multiplex panel. RESULTS: After correction for multiple comparisons, only CSF IL-12/23 p40 concentration differed significantly between the total patient group (n = 52) and controls (n = 18; p = 0.002). Further analyses showed that CSF IL-12/23 p40 concentration was decreased in all patient subgroups (AD, other dementias, and SMCI) compared to healthy controls (p < 0.01, p < 0.05, and p < 0.05, respectively). In the total study population (n = 70), CSF IL-12/23 p40 concentrations correlated positively with CSF concentrations of β-amyloid₁-₄₂ (Aβ₁-₄₂) and phosphorylated tau protein (P-tau) whereas in AD patients (n = 30), CSF IL-12/23 p40 only correlated positively with CSF P-Tau (r = 0.46, p = 0.01). CONCLUSIONS: Most cytokines and chemokines were similar in patients and controls, but CSF IL-12/23 subunit p40 concentration was decreased in patients with cognitive impairment, and correlated with markers of AD disease status. Further studies are needed to evaluate the role of CSF IL-12/23 p40 in other dementias and SMC
Heavy Meson Production in Proton-Nucleus Reactions with Empirical Spectral Functions
We study the production of and mesons in reactions on the basis of empirical spectral functions. The high
momentum, high removal energy part of the spectral function is found to be
negligible in all cases close to the absolute threshold. Furthermore, the
two-step process () dominates the cross section at threshold energies in line with
earlier calculations based on the folding model.Comment: 18 pages, LaTeX, plus 14 postscript figures, submitted to Z. Phys.
Definitions and operationalization of mental health problems, wellbeing and participation constructs in children with NDD: distinctions and clarifications
Children with impairments are known to experience more restricted participation than other children. It also appears that low levels of participation are related to a higher prevalence of mental health problems in children with neurodevelopmental disorders (NDD). The purpose of this conceptual paper is to describe and define the constructs mental health problems, mental health, and participation to ensure that future research investigating participation as a means to mental health in children and adolescents with NDD is founded on conceptual clarity. We first discuss the difference between two aspects of mental health problems, namely mental disorder and mental illness. This discussion serves to highlight three areas of conceptual difficulty and their consequences for understanding the mental health of children with NDD that we then consider in the article: (1) how to define mental health problems, (2) how to define and assess mental health problems and mental health, i.e., wellbeing as separate constructs, and (3) how to describe the relationship between participation and wellbeing. We then discuss the implications of our propositions for measurement and the use of participation interventions as a means to enhance mental health (defined as wellbeing). Conclusions: Mental disorders include both diagnoses related to impairments in the developmental period, i.e., NDD and diagnoses related to mental illness. These two types of mental disorders must be separated. Children with NDD, just like other people, may exhibit aspects of both mental health problems and wellbeing simultaneously. Measures of wellbeing defined as a continuum from flourishing to languishing for children with NDD need to be designed and evaluated. Wellbeing can lead to further participation and act to protect from mental health problems
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