[Comparative analysis of in vitro test procedures for evaluating hemocompatibility of cardiovascular stents]. / Vergleichende Analyse von in vitro Testverfahren zur Beurteilung der Hämokompatibilität von kardiovaskulären Stents.

Within the scope of this study existing in vitro techniques for testing the hemocompatibility of coronary stents were analysed and optimised. Static and quasi-stationary systems were compared to a pulsed flow model with respect to platelet activity. The streamlines were visualized by dye injection. Blood flow was measured by ultrasonic Doppler velocity meter and electromagnetic flow meter. Uncoated stainless steel (316 L) stents were tested. Surrogate parameters of the hemocompatibility were the change in surface morphology after blood contact and the rise of biomechanical activation markers as C3a and beta-thromboglobulin. The results were correlated to the stent design and to the flow characteristics of the test systems.

Assessment of explanted PTCA balloons.

The data presented here are part of a on-going study to define the surface characteristics and properties of explanted PTCA catheters in a further effort to address some of the ramifications of the re-use issue. PTCA balloon catheter were examined after angioplasty in one hundred and sixty-eight patients (n = 168). This series included six balloon types from three manufacturers. The fresh fixed and dehydrated balloons were examined at first with light microscopy and then in a scanning electron microscope. X-ray semiquantitative microanalysis and FT-IR-ATR analysis were also performed on the balloons. Because most blood proteins are water soluble, we examined unfixed balloons with a protein silver staining kit for detection of adhered proteins described by Heukeshoven. A further method for protein detection is the Lowry-analysis. With this method water insoluble proteins can be observed. Our study has shown convincingly that all deployed angioplasty catheters were coated with adherent protein layers. Plaque particles were found embedded in the surfaces of most of the balloons examined. Fissuring and micro tearing of balloon surfaces was noted. FT-IR-ATR analyses of the blood contacted balloon surfaces did not show any peaks indicative of proteins on the balloon surface. The silver staining method also did not show any evidence of protein adsorption on the balloons. On the other hand, the Lowry-analysis yielded clear evidence that water insoluble proteins were adherent to the balloon surfaces. The average measured protein concentration was 17 microg/ml.

Photoassociation of cold Ca atoms

We present the first measurement of a photoassociative spectrum of an alkaline earth element near the dissociation limit. The observed spectrum of Ca2 formed from cold atoms shows the regular vibrational series with the characteristic spacing of the 1/R3 asymptotic potential. The interpretation is in principle simplified compared to previous measurements on alkali metals by the nondegenerate ground state and the missing hyperfine structure of 40Ca. As an example, we derive the natural decay rate of the excited atomic 4p 1P1 state from the positions of the observed vibrational and rotational resonances with reduced uncertainty compared to previous measurements.

[Thallium myocardial scintigraphy, hemodynamics and left ventricular wall kinetics in patients with suspected myocardial sarcoidosis]. / Thallium-Myokardszintigraphie, Hämodynamik und Linkskammerwandkinetik bei Patienten mit Verdacht auf Myokardsarkoidose.

The cardiological examination of 22 patients (pts) with suspected heart sarcoidosis (histologically established lung sarcoidosis, heart rhythm disturbances, cardiomegaly) has revealed thallium scan defects in 20 pts at rest and during exercise. In 19 pts we found pathologic left heart wall motions established by laevocardiography by applying the half axis method. The number of pathologic half axis shortenings correlated with ejection fraction, but not with left ventricular enddiastolic pressure and left ventricular enddiastolic volume index. IHD could not be found in coronarography in any case. Myocardial biopsy did not show myocarditis. Cardiomyopathies, other specific heart muscle diseases or rheumatic myocarditis could not be excluded as causes of the results mentioned above. The follow-up examinations of the patients will give more detailed information on the etiology of the pathologic cardiac findings.

[Follow-up studies and special cardiologic diagnosis in patients with suspected heart sarcoidosis]. / Verlaufsbeobachtungen und spezielle kardiologische Diagnostik bei Patienten mit Verdacht auf Herzsarkoidose.

During a retrospective analysis of 1236 patients with pulmonary sarcoidosis who showed electrocardiographic disturbances or cardiomegaly the existence of a possible heart sarcoidosis was suspected. It was tried to confirm this suspected diagnosis in subsequent examinations of these patients by support of modern non-invasive and invasive cardiological methods. Thereby the differential diagnosis to the coronary heart disease is especially difficult in elderly. This problem represents a permanent diagnostic challenge because of the therapeutic chance in case of heart sarcoidosis.

[Immunoadsorption using Staphylococcus aureus, COWAN I strain]. / Immunadsorption mittels Staphlokokkus aureus, Stamm COWAN I.

Immunoadsorbents bind immunoglobulins, immunocomplexes or immunocytes. Their clinical use could become a new therapeutic principle for diseases in the pathogenesis of which antibodies or immunocomplexes play an important part. Immunoadsorbents are also being tested in the hope that they can at least partially replace the plasmapheresis-plasma exchange therapy at present practised. A report is given on in-vitro studies using protein-A-bearing staphylococci, strain COWAN I. The bacteria bind IgG selectively, IgM to a small extent, IgA, IgD and IgE hardly. The majority of the other plasma proteins tested (e.g. albumin, transferrin, ceruloplasmin, alpha-2-macroglobulin, beta-lipoprotein, alpha-2-glycoprotein, alpha-1-antitrypsin) are bound only non-specifically and in small quantities. The staphylococci can react with acid solutions (glycin-HCl buffer, acetic acid) in several ways. The activation of the complement system by IgG binding to protein A is one of the problems to be solved before immunoadsorbents an be used clinically.