ABSTRACT
BACKGROUND: Heart valve computational models require high quality geometric input data, commonly obtained using micro-computed tomography. Whether in the open or closed configuration, most studies utilize dry valves, which poses significant challenges including gravitational and surface tension effects along with desiccation induced mechanical changes. OBJECTIVE: These challenges are overcome by scanning in a stress-free configuration in fluid. Utilizing fluid backgrounds however reduces overall contrast due to the similar density of fluid and tissue. METHODS: The work presented here demonstrates imaging of the mitral valve by utilizing an iodine-based staining solution to improve the contrast of valve tissue against a fluid background and investigates the role of stain time and concentration. RESULTS: It is determined that an Olea europaea oil bath with a relatively high concentration, short stain time approach produces high quality imagery suitable for creating accurate 3D renderings. CONCLUSIONS: Micro-CT scanning of heart valves in fluid is shown to be feasible using iodine staining techniques.
ABSTRACT
On the basis of statistics on erythrocyte antibodies annually transmitted to the Ministry of Health by the institutions of blood transfusion service in the GDR, an analysis on frequency, population and distribution of specificity to be found in erythrocyte antibodies was established for the first time from 1978 to 1980. For the time covered by the investigation, the GDR percentage of the total detection rate for antibodies amounted to 0.39%, with a fluctuating range of 0.14% to 0.7% being present in the various districts. Even the percentages of immunoantibodies and natural antibodies greatly differed within the country. Anti-D could be identified as the most frequent antibody. Moreover, the specificities anti-E, anti-P1, anti-Lea, anti-D + C and anti-Lea + Leb were significant in their number. The variety of antibodies detected justifies the necessity of consequently applying antibody screenings in the pretransfusional serology of hospitals. The percentage of antibodies predominantly identified by the indirect antihuman globulin test has to be enhanced by the continual application of this method.