Detection of total- and partial-body irradiation in a monkey model: a comparative study of chromosomal aberration, micronucleus and premature chromosome condensation assays.

Purpose: To investigate the efficacy of three cytogenetic methods (dicentrics, micronuclei (MN) and premature chromosome condensation (PCC) analysis) for assessment of the unirradiated fraction and the persistence of damage after total-body (TB) and partial-body (PB) irradiation of rhesus monkeys (Macaca mulatta).

Materials And Methods: Animals were exposed to X-rays (5 Gy), either TB or PB, with about 6% of marrow cells shielded. Blood samples were collected at different times after exposure, i.

PCDOSE: an interactive software system to calculate internal radiation dose on a personal computer.

An interactive, menu directed, software system to calculate committed dose equivalents for individuals with different physiques after inhalation, ingestion or injection of radionuclides has been developed. The calculations are based on ICRP 26/30 methods. The programs are written in PASCAL and can be implemented on a personal computer with a MS-DOS operating system and a hard disk with a storage capacity of at least 20 Mb.

Models for the electronic processing of flow cytometric data at high particle rates.

In flow cytometry at high particle rates, complete processing of data is limited by the capacity of the flow cytometer electronics which are constrained by the waiting or cycling time of the processor. Four models of impulse processors were analyzed to study the influence of the waiting time and reset mechanisms on the input-output properties of commonly used electronic devices. The models contain a feedback loop to represent a waiting time and describe reset mechanisms to filter trains of consecutive pulses such as clumps and doublets.

Coincidence in high-speed flow cytometry: models and measurements.

In flow cytometry, the coincident arrival of particles becomes a major problem when high sample rates are required. For the development of our high-speed photodamage flow cytometer (ZAPPER), it was of importance to understand the behavior of cells at flow rates of around 50,000-250,000 event/s. We developed and compared two models that describe the relation between the real cell rate and the detectable single cell rate.

Confocal microscopy as a tool for the study of the intranuclear topography of chromosomes.

A scanning confocal microscope was used to investigate the spatial positions of specific regions within blood cell nuclei. These centromeric regions were fluorescently labelled by in-situ hybridization to suspended nuclei with a centromere-1-specific DNA probe. The 3-D image data sets, obtained by optical sectioning of the cells, were used to determine the spatial position of the centromeric regions in the nuclei by means of specially developed software.