Biomedical subjects

H W Gantenberg

Publications and source records attributed to H W Gantenberg.

2 recordsLinked to original sources

PubMed1996

Automated cell cycle analysis with fluorescence microscopy and image analysis.

Automatic cell cycle analysis (DNA histograms) is usually performed with flow cytometry. In cases when only few cells are available, the DNA content has to be measured with a fluorescence microscope combined with sensitive camera systems (SIT, MCP, cooled CCDs) and a frame grabber for image analysis. The fluorescent cells are observed on the monitor of the image analyser. The DNA content of specific cells of interest is calculated after an interactive selection via mouse click on the monitor screen. It is desirable to automate this time-consuming procedure by a computer "cell-finding' and "cell-measurement' system, which is comparable in speed and measurement accuracy with manual scoring. A software program, based on image analysis, was designed for the automated cell finding, the cell measurement, and finally the interactive DNA data evaluation. The system has already been used to determine cell cycle stages in which specific manipulations of a lymphocyte culture were required. However, the system is also able to determine, automatically, DNA distributions of different kinds of cell (different leucocytes) within one sample, as long as the automatic recognition software can distinguish between them by morphological differences.

Algorithms↗

PubMed1991

Micronuclei in human lymphocytes irradiated in vitro or in vivo.

Venous blood from healthy donors or from patients with various lympho- and myeloproliferative diseases was incubated in vitro in the presence of cytochalasin B for the induction of binucleated lymphocytes. The time at which cytochalasin B was added depended on the proliferation rate of the lymphocytes. Proliferation was monitored using a semiautomatic microscope photometer/computer system. The background level of micronuclei in binucleated lymphocytes of the patients before radiotherapy was statistically indistinguishable from that of healthy persons. Blood from both groups was irradiated in vitro for the study of the dose-response relationship. The dose-response curves were very similar up to 3.75 Gy, and a somewhat lower micronucleus frequency was found in lymphocytes of patients after a 5-Gy exposure. These in vitro results were compared with in vivo exposure after total-body irradiation of leukemic patients. Due to heavy medication that accompanied radiation therapy, only two doses (1.25 and 2.5 Gy) could be checked after in vivo exposure. There was no statistically significant difference between in vitro and in vivo results after 1.25 Gy, but a slightly lower number of micronuclei was observed after in vivo exposure to 2.5 Gy.

Adult↗