N. Zimmermann

Learn More
Cerium-III-ions are more and more used as capturing reagent and opaque marker for the electron microscopic localization of a number of H2O2-generating enzymes as well as phosphohydrolases. Contrary to its advantages over common lead methods in the histochemical detection of enzyme activities at the electron microscopic level, cerium-based methods proved to(More)
New light microscopic visualization methods were developed for the histochemical detection of non-specific alkaline and acid phosphatase, Mg-, Ca- and Na, K-dependent adenosine triphosphatase, myosin adenosine triphosphatase, glucose-6-phosphatase, 5'-nucleotidase and thiamine pyrophosphatase with cerium ions as trapping agents in cryostat and plastic(More)
In this paper we present an approach for interactive visualization and manipulation of huge point clouds. Archaeological monuments like the Domitilla Catacomb in Rome lead to data sets surpassing 1 Billion (109) points or 20GB of storage space, which makes standard techniques like mesh conversion or in-core point-based rendering infeasible. Our system uses(More)
During physiologic aging, erythrocytes (RBC) mainly loose membrane as shown by biochemical investigations. The most likely reason for a such loss would be the pinch off of RBC-microvesicles. The detection of RBC-microvesicles generated in vivo is rendered more difficult because of the relatively small amount of vesiculation processes under physiologic(More)
Cytophotometric evaluation of mouse sperm glucose-6-phosphate dehydrogenase revealed a single peak-curve of enzyme activity. The finding is clearly contrary to the assumption of postmeiotic transcription of the X-chromosomal G6PDH-gene which was considered a possible source of increased enzyme activity in mature sperm cells.
A modification of the earlier published cerium-based technique for histochemical detection of alkaline phosphatase activity at light microscopical level (Halbhuber and Zimmermann 1985) is described. The reduction of the s-collidine concentration from 200 mmol to 50 mmol, increase of cerium ion concentration rom 1 mmol to 5 or 10 mmol, and sucrose(More)
The expression of IgG receptor sites during aging of red blood cells plays an important role in the elimination process of these cells by the Reticulo Histiocytic System. By means of an indirect protein A gold-method, membrane bound IgG was detected immunocytochemically on pronase and neuraminidase treated red blood cells as well as on physiologically aged(More)
In a comparative study of red cells from concentrates preserved in SAG medium without and with 30 mM sucrose, mannitol or sorbitol, resp., we determined the variation of IgG binding, osmotic fragility, MCV and the surface area index with storage time. IgG binding gave no conclusive results. Osmotic fragility turned out to be increased in simple SAG in(More)
The extent of the splenal transit time is an important factor which influences the immunological behaviour of the red blood cells. An increased transit time of the RBC in the splenal reticulum leads to conformational effects on the erythrocyte glycocalyx. They consist in spatial disorder of the oligosaccharide side chains of the glycophorins with their(More)