20 research outputs found
Zum Stellenwert der kardialen Magnetresonanztomographie in der Diagnostik der Arrhythmogenen RechtsventrikulÀren Kardiomyopathie (ARVC)
Zusammenfassung Stellenwert der MRT in der Diagnostik der ARVC
Fragestellung: 1. MRT in der Diagnose der ARVC gegenĂŒber Differentialdiagnosen, 2. Ergebniskorrelation MRT vs. Ventrikulographie/Biopsie, 3. MRT-Benefit fĂŒr ARVC DiagnoseĂŒberfĂŒhrung 4. Anzahl der ARVC durch MRT 5. MRT-PhĂ€notyp bei PKP-2-Mutation
Methodik: 113 MR-tomographisch untersuchte Patienten mit gesicherter ARVC (n=24) oder nachzuweisender/auszuschlieĂender ARVC bei klinischem Verdacht (n=22), positiver Familienanamnese fĂŒr ARVC (n=22), rechtsventrikulĂ€rer Ausflusstrakttachykardie (n=22), Brugada-Syndrom (n=15) oder ventrikulĂ€ren Extrasystolen (n=8).
Ergebnisse: Wandbewegungsstörungen zeigten höchste Ăbereinstimmung mit dem Referenzstandard. FĂŒr die quantitative RV-Funktion zeigten sich statistisch signifikante Unterschiede zwischen ARVC und Vergleichskollektiven (p<0,05). Der Zugewinn der MRT zur Diagnose ARVC betrug 9 Patienten. Es zeigte sich ein Zusammenhang zwischen PKP-2 positivem Genotyp und MR-PhĂ€notyp
The two-angle model and the phase diagram for Chromatin
We have studied the phase diagram for chromatin within the framework of the
two-angle model. Rather than improving existing models with finer details our
main focus of the work is getting mathematically rigorous results on the
structure, especially on the excluded volume effects and the effects on the
energy due to the long-range forces and their screening. Thus we present a
phase diagram for the allowed conformations and the Coulomb energies
The influence of the cylindrical shape of the nucleosomes and H1 defects on properties of chromatin
We present a model improving the two-angle model for interphase chromatin
(E2A model). This model takes into account the cylindrical shape of the histone
octamers, the H1 histones in front of the nucleosomes and the vertical distance
between the in and outgoing DNA strands. Factoring these chromatin features
in, one gets essential changes in the chromatin phase diagram: Not only the
shape of the excluded-volume borderline changes but also the vertical distance
has a dramatic influence on the forbidden area. Furthermore, we examined
the influence of H1 defects on the properties of the chromatin fiber. Thus we
present two possible strategies for chromatin compaction: The use of very dense
states in the phase diagram in the gaps in the excluded volume borderline or
missing H1 histones which can lead to very compact fibers. The chromatin fiber
might use both of these mechanisms to compact itself at least locally. Line
densities computed within the model coincident with the experimental values
Biventricular myocardial strain analysis in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) using cardiovascular magnetic resonance feature tracking
BACKGROUND: Fibrofatty degeneration of myocardium in ARVC is associated with wall motion abnormalities. The aim of this study was to examine whether Cardiovascular Magnetic Resonance (CMR) based strain analysis using feature tracking (FT) can serve as a quantifiable measure to confirm global and regional ventricular dysfunction in ARVC patients and support the early detection of ARVC. METHODS: We enrolled 20 patients with ARVC, 30 with borderline ARVC and 22 subjects with a positive family history but no clinical signs of a manifest ARVC. 10 healthy volunteers (HV) served as controls. 15 ARVC patients received genotyping for Plakophilin-2 mutation (PKP-2), of which 7 were found to be positive. Cine MR datasets of all subjects were assessed for myocardial strain using FT (TomTec Diogenes Software). Global strain and strain rate in radial, circumferential and longitudinal mode were assessed for the right and left ventricle. In addition strain analysis at a segmental level was performed for the right ventricular free wall. RESULTS: RV global longitudinal strain rates in ARVC (â0.68 ± 0.36 sec(â1)) and borderline ARVC (â0.85 ± 0.36 sec(â1)) were significantly reduced in comparison with HV (â1.38 ± 0.52 sec(â1), pââ€â0.05). Furthermore, in ARVC patients RV global circumferential strain and strain rates at the basal level were significantly reduced compared with HV (strain: â5.1 ± 2.7 vs. -9.2 ± 3.6%; strain rate: â0.31 ± 0.13 sec(â1) vs. -0.61 ± 0.21 sec(â1)). Even for patients with ARVC or borderline ARVC and normal RV ejection fraction (n=30) global longitudinal strain rate proved to be significantly reduced compared with HV (â0.9 ± 0.3 vs. -1.4 ± 0.5 sec(â1); p < 0.005). In ARVC patients with PKP-2 mutation there was a clear trend towards a more pronounced impairment in RV global longitudinal strain rate. On ROC analysis RV global longitudinal strain rate and circumferential strain rate at the basal level proved to be the best discriminators between ARVC patients and HV (AUC: 0.9 and 0.92, respectively). CONCLUSION: CMR based strain analysis using FT is an objective and useful measure for quantification of wall motion abnormalities in ARVC. It allows differentiation between manifest or borderline ARVC and HV, even if ejection fraction is still normal
Monte Carlo Simulations indicate that Chromati: Nanostructure is accessible by Light Microscopy
A long controversy exists about the structure of chromatin. Theoretically, this structure could be resolved by scattering experiments if one determines the scattering function - or equivalently the pair distribution function - of the nucleosomes. Unfortunately, scattering experiments with live cells are very difficult and limited to only a couple of nucleosomes
Johann Heermanns geistliche Lieder
Layoutgetreues Digitalisat der Ausg.: Stuttgart : Liesching, 1856. -
Standort: UniversitÀt Marburg, Bibliothek Evangelische Theologie [381] (Gesangbuchsammlung)
Signatur: PTh Dp Hee 1856 sekr. -
Bemerkungen: In Fraktur. -
Digitalisiert 201
Holoprosencephaly with a Special Form of Anophthalmia Result from Experimental Induction of <i>bmp4</i>, Oversaturating BMP Antagonists in Zebrafish
Vision is likely our most prominent sense and a correct development of the eye is at its basis. Early eye development is tightly connected to the development of the forebrain. A single eye field and the prospective telencephalon are situated within the anterior neural plate (ANP). During normal development, both domains are split and consecutively, two optic vesicles and two telencephalic lobes emerge. If this process is hampered, the domains remain condensed at the midline. The resulting developmental disorder is termed holoprosencephaly (HPE). The typical ocular finding associated with intense forms of HPE is cyclopia. However, also anophthalmia and coloboma can be associated with HPE. Here, we report that a correct balance of Bone morphogenetic proteins (BMPs) and their antagonists are important for forebrain and eye field cleavage. Experimental induction of a BMP ligand results in a severe form of HPE showing anophthalmia. We identified a dysmorphic forebrain containing retinal progenitors, which we termed crypt-oculoid. Optic vesicle evagination is impaired due to a loss of rx3 and, consecutively, of cxcr4a. Our data further suggest that the subduction of prospective hypothalamic cells during neurulation and neural keel formation is affected by the induction of a BMP ligand
The characterization and certification of a quantitative reference material for Legionella detection and quantification by qPCR.
International audienceAIMS: The characterization and certification of a Legionella DNA quantitative reference material as a primary measurement standard for Legionella qPCR. METHODS AND RESULTS: Twelve laboratories participated in a collaborative certification campaign. A candidate reference DNA material was analysed through PCR-based limiting dilution assays (LDAs). The validated data were used to statistically assign both a reference value and an associated uncertainty to the reference material. CONCLUSIONS: This LDA method allowed for the direct quantification of the amount of Legionella DNA per tube in genomic units (GU) and the determination of the associated uncertainties. This method could be used for the certification of all types of microbiological standards for qPCR. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of this primary standard will improve the accuracy of Legionella qPCR measurements and the overall consistency of these measurements among different laboratories. The extensive use of this certified reference material (CRM) has been integrated in the French standard NF T90-471 (April 2010) and in the ISO Technical Specification 12Â 869 (Anon 2012 International Standardisation Organisation) for validating qPCR methods and ensuring the reliability of these methods