TY  - JOUR
A1  - Pressler, Axel
A1  - Esefeld, Katrin
A1  - Scherr, Johannes
A1  - Ali, Mohammad
A1  - Hanssen, Henner
A1  - Kotliar, Konstantin
A1  - Lanzl, Ines
A1  - Halle, Martin
A1  - Kaemmerer, Harald
A1  - Schmidt-Trucksäss, Arno
A1  - Hager, Alfred
T1  - Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation
JF  - The American Journal of Cardiology
N2  - Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5%, first to third quartile 2.1% to 4.5% vs 3.6%, first to third quartile 2.2% to 4.3%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.
Y1  - 2010
U6  - http://dx.doi.org/10.1016/j.amjcard.2009.10.070
SN  - 0002-9149
VL  - 105
IS  - 5
SP  - 740
EP  - 744
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kotliar, Konstantin
A1  - Lanzl, Ines M.
A1  - Schmidt-Trucksäss, A.
A1  - Sitnikova, Diana
A1  - Ali, Mohammad
A1  - Blume, Katharina
A1  - Halle, Martin
A1  - Hansser, Henner
T1  - Dynamic retinal vessel response to flicker in obesity: A methodological approach
JF  - Microvascular Research
Y1  - 2011
SN  - 0026-2862
VL  - 81
IS  - 1
SP  - 123
EP  - 128
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Pourshahidi, Mohammad Ali
A1  - Shalaby, Ahmed
A1  - Krause, Hans-Joachim
T1  - Probing particle size dependency of frequency mixing magnetic detection with dynamic relaxation simulation
JF  - Journal of Magnetism and Magnetic Materials
N2  - Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles’ magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning  nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing.
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.jmmm.2022.169965
SN  - 0304-8853
VL  - 563
IS  - In progress, Art. No. 169965
PB  - Elsevier
CY  - Amsterdam
ER  -