In the final years of his life, Felix Dörmann wrote his only two novels: Jazz (1925) and Machen Sie mich zu Ihrer Geliebten! (1928). These Zeitromane depict the political, economic, and cultural turbulence of the interwar years in Europe and, more specifically, Austria. Dörmann portrays the dissolution of traditional sources of authority as wealth increasingly becomes the sole guarantor of power. The two novels expose the dangers of this situation to individuals and society by interrogating the categories of time and space. Jazz depicts an Austrian modernity in which heritage and present desires struggle, with fatal consequences, against a future- oriented economic order characterized by relentless change. Machen Sie mich zu Ihrer Geliebten! details the existential threat posed to Austrian sovereignty by the burgeoning globalization of private capital and the concomitant rise of an international elite. Dörmann's novels offer no solutions to these dangers, which consequently seem to herald Austria's impending downfall.
The choice of parameters for laser beams used in the treatment of musculoskeletal diseases is of great importance. First, to reach high penetration depths into biological tissue and, secondly, to achieve the required effects on a molecular level. The penetration depth depends on the wavelength since there are multiple light-absorbing and scattering molecules in tissue with different absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology. Penetration depths in two types of tissue ex vivo (porcine skin and bovine muscle) were investigated. The transmittance of 1064 nm light through both tissue types was consistently higher than of 905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the difference vanished with increasing tissue thickness. Overall, the differences in penetration depth were comparably small. These results may be of relevance in the selection of a certain wavelength in the treatment of musculoskeletal diseases with laser therapy.
Current techniques to resolve heart valve defects involve the use of prosthetic and bioprosthetic materials. These materials lack the potential to grow and are not ideal, especially not for pediatric patients. Novel techniques like tissue engineering involve the use of biodegradable polymers coated with autologous myofibroblast and endothelial cells. We inspected morphological and marker gene expression differences between cells harvested from the saphenous vein, or from veins and arteries of the umbilical cord, and the cells they are designed to replace: the interstitial and endothelial cells of the pulmonary heart valve. We assessed the extent to which the endothelial cells from the inspected sources in vitro resemble endothelial cells of human pulmonary heart valves, and we found that myofibroblast cells, respective of their source, in vitro differ from the interstitial cells from human pulmonary heart valves regarding collagen and smooth muscle alpha-actin. Therefore we conclude that the cells isolated from the saphenous veins, or from veins and arteries of the umbilical cord might be feasible cell sources for tissue engineering of heart valve for the pulmonary position.
Background: Pressure recovery is not taken into account when calculating transprosthetic gradients after mechanical valve replacement using Doppler echocardiography. This may lead to underestimation of valvular performance. Methods: Simultaneous measurement of Doppler and direct transprosthetic gradients was performed in a circulatory mock loop simulator with physiologic parameters at different heart rates and cardiac outputs for small-sized aortic Omnicarbon™ tilting disc valves (19 - 21 mm). Results: In all adjustments the Doppler gradient significantly overestimated the net transvalvular gradient. The amount of pressure recovery averaged 59.3 %. Conclusions: Doppler echocardiography does not allow for pressure recovery, which is a significant phenomenon in the hemodynamic function of the Omnicarbon™ tilting disc valve. Valve performance is much better than expected from Doppler gradients.
Valve-preserving aortic replacement has become an accepted option for patients with aortic valve regurgitation and aortic dilatation. The relative role of root remodeling versus valve reimplantation inside a vascular graft has been discussed, albeit controversially. In the present study, an in-vitro model was used to investigate the aortic valve hemodynamics of root remodeling and valve reimplantation; roots with supracommissural aortic replacement served as controls.Aortic roots with aortoventricular diameter 21 mm were obtained from pigs. Root remodeling was performed using a 22-mm graft (group I, n = 6), or valve reimplantation with a 24-mm graft (group II, n = 7). Control roots were treated by supracommissural aortic replacement (22-mm graft; group III, n = 7). Using an electrohydraulic, computer-controlled pulse duplicator, the valves were tested at flows of 2, 4, 5, 7, and 9 I/min at a heart rate of 70 /min and a mean arterial pressure of 100 mmHg. Parameters assessed included: mean pressure gradient, effective orifice area, valve closure and regurgitant volume, and energy loss due to ejection, valve closure and regurgitation. Data were compared using ANOVA.There were no differences between the three groups in terms of regurgitant volume, energy loss due to valve regurgitation, or valve closure. The aortic valve orifice area was largest and systolic gradient lowest in group I at all flow rates (p < 0.001). Ejection energy loss was lowest in group I at all flow rates (9 l/min: group I, 128 +/- 21 mJ; group II, 399 +/- 46 mJ; group III, 312 +/- 27 mJ; p < 0.001). Valve closure volumes were similar in groups I and III, but significantly lower in group II at all flow rates (p = 0.047).In this standardized experimental setting, root remodeling--but not valve reimplantation--resulted in physiologic hemodynamic performance of the aortic valve with regard to orifice area, pressure gradient, and systolic energy loss.
To assess the feasibility of transcatheter aortic valve implantation (TAVI; Medtronic CoreValve and Edwards SAPIEN XT) under local anaesthesia with only mild analgesic medication and fluoroscopic guidance.461 patients underwent TAVI under local anaesthesia with lidocaine. The procedure was performed successfully in 459 of the cases. All patients were also treated with piritramide, metoclopramide hydrochloride and 62 mg dimenhydrinate. Monitoring consisted of a six-electrode, virtual 12-lead ECG, pulse oximetry, and invasive arterial pressure measurement. There was no continuous surveillance by an anaesthesiologist.There was no need for conversion to general anaesthesia except in four patients who required cardiopulmonary resuscitation. Conscious sedation with intravenous administration of midazolam for agitation or inotropic medication for prolonged hypotension was necessary in only seven of the 461 patients. The combined safety end point according to the Valve Academic Research Consortium consensus document was reached in 12.6%.Our results show that TAVI performed under local anaesthesia with only mild analgesic medication and under fluoroscopic guidance is feasible, with good outcome comparable to published data.
After myocardial infarction, the implantation of stem cell seeded scaffolds on the ischemic zone represents a promising strategy for restoration of heart function. However, mechanical integrity and functionality of tissue engineered constructs need to be determined prior to implantation. Therefore, in this study a novel pulsatile bioreactor mimicking the myocardial contraction was developed to analyze the behavior of mesenchymal stem cells derived from umbilical cord tissue (UCMSC) colonized on titanium-coated polytetrafluorethylene scaffolds to friction stress. The design of the bioreactor enables a simple handling and defined mechanical forces on three seeded scaffolds at physiological conditions. The compact system made of acrylic glass, Teflon®, silicone, and stainless steel allows the comparison of different media, cells and scaffolds. The bioreactor can be gas sterilized and actuated in a standard incubator. Macroscopic observations and pressure-measurements showed a uniformly sinusoidal pulsation, indicating that the bioreactor performed well. Preliminary experiments to determine the adherence rate and morphology of UCMSC after mechanical loadings showed an almost confluent cellular coating without damage on the cell surface. In summary, the bioreactor is an adequate tool for the mechanical stress of seeded scaffolds and offers dynamic stimuli for pre-conditioning of cardiac tissue engineered constructs in vitro.
