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Biomedical subjects

S Schwarzer

Publications and source records attributed to S Schwarzer.

12 recordsLinked to original sources
PubMed2000

Navier-Stokes simulation with constraint forces: finite-difference method for particle-laden flows and complex geometries.

Building on an idea of Fogelson and Peskin [J. Comput. Phys. 79, 50 (1988)] we describe the implementation and verification of a simulation technique for systems of non-Brownian particles in fluids at Reynolds numbers up to about 20 on the particle scale. This direct simulation technique fills a gap between simulations in the viscous regime and high-Reynolds-number modeling. It also combines sufficient computational accuracy with numerical efficiency and allows studies of several thousand, in principle arbitrarily shaped, extended and hydrodynamically interacting particles on regular work stations. We verify the algorithm in two and three dimensions for (i) single falling particles and (ii) a fluid flowing through a bed of fixed spheres. In the context of sedimentation we compute the volume fraction dependence of the mean sedimentation velocity. The results are compared with experimental and other numerical results both in the viscous and inertial regime and we find very satisfactory agreement.

Algorithms↗
PubMed1995

Determination of fractal dimension of physiologically characterized neurons in two and three dimensions.

Although there is a growing interest in the application of fractal analysis in neurobiology, questions about the methodology have restricted its wider application. In this report we discuss some of the underlying principles for fractal analysis, we propose the cumulative-mass method as a standard method and we extend the applicability of fractal analysis to both 2 and 3 dimensions. We have examined the relationship between the method of log-log Sholl analysis and fractal analysis and have found that they correlate well. Measurements of physiologically characterized retinal ganglion cells indicate that different cell types can have significantly different fractal dimensions. Such differences may allow the correlation of the physiological type of a neuron with its morphological fractal dimension.

Animals↗
PubMed1991

Non-Q-wave myocardial infarction associated with bleomycin and etoposide chemotherapy.

During chemotherapy with bleomycin and etoposide a 28-year-old male, suffering from germ-cell cancer, developed acute myocardial infarction. Under treatment with heparin and aspirin the patient revealed no Q-waves in ECG and recovery was without complications. Four weeks after onset of infarction, thallium-201 scintigraphy showed only a small irreversible, posteroseptal perfusion defect; coronary angiography was not performed. The chemotherapy regimen was continued and modified to etoposide as well as cisplatin and ifosfamide without recurrence of cardiac symptoms or ECG changes.

Adult↗
PubMedDate not supplied

Safety and characterization of the immune response engendered by two combined measles, mumps and rubella vaccines.

We performed a randomized trial to compare the safety and immunogenicity of two combined measles, mumps and rubella vaccines in healthy children 14-24 months of age. Triviraten Berna Vaccine (Swiss Serum and Vaccine Institute), contains the Edmonston Zagreb 19 strain of measles virus, the Rubini mumps virus strain and the Wistar RA 27/3 rubella strain while MMR-Vax (Merck, Sharp & Dohme, West Point, PA) contains the Enders attenuated Edmonston measles strain, the Jeryl Lynn mumps strain and the Wistar RA 27/3 rubella strain. Immunization with Triviraten Berna was associated with a significantly lower incidence of swelling and redness at the injection site in addition to a reduced rate of fever compared with MMR-Vax. Seroconversion rates for the measles and rubella vaccine components were comparable in all tests used. However, seroconversion for the mumps vaccine component was test-dependent. Using an ELISA, the seroconversion rate following immunization with MMR-Vax was significantly (P < 0.01) higher than for Triviraten Berna. In contrast, nearly identical rates were obtained using an indirect immunofluorescence test. Both vaccines were equally effective at engendering antibodies capable of neutralizing wild type mumps virus. Geometric mean ELISA antibody titers against measles and mumps virus were higher following immunization with MMR-Vax while that for rubella was higher after immunization with Triviraten Berna. A small number (N = 13) of adolescents immunized either with MMR-Vax or Triviraten Berna were reimmunized with Triviraten Berna and various humoral and cellular response parameters to the measles and mumps vaccine components analyzed. While few subjects mounted a humoral antibody response to measles, most likely due to elevated baseline titers, there was a marked lymphoproliferative response. Anti-mumps virus ELISA antibody titers were higher both at baseline and after reimmunization in subjects who received MMR-Vax for primary immunization. However, there was no difference in either neutralizing titer or proliferative response in subjects primed with MMR-Vax or Triviraten Berna either before or after reimmunization.

Antibodies, Viral↗