HIF-1A, pimonidazole, and iododeoxyuridine to estimate hypoxia and perfusion in human head-and-neck tumors.

Purpose: Tumor hypoxia measured by microelectrodes has been shown to indicate poor patient outcome. Here we investigated four potentially more widely applicable immunohistochemical parameters of tumor oxygenation and perfusion in human head-and-neck tumors.

Methods: Twenty patients with squamous cell carcinomas of the head and neck treated with primary surgery were injected with pimonidazole and IdUrd the evening before operation.

Hypoxia and perfusion measurements in human tumors--initial experience with pimonidazole and IUdR.

We describe our preliminary studies on the development of methods to measure hypoxia in standard paraffin sections of human tumors. Three parameters were investigated. First, image analysis of tumor vascularity yielded the parameter diffusion limited fraction (DLF), which is the amount of tumor tissue greater than a fixed distance from the nearest blood vessel.

Automatic detection of stable and unstable chromosome aberrations visualized by three-color imaging after fluorescence in situ hybridization with a painting and a pancentromeric DNA probe.

Two-color fluorescence in situ hybridization (FISH) in combination with digital image analysis was used to develop an automatic system for the detection and classification of chromosome aberrations. Algorithms were developed for the automatic thresholding of the three digitized images: an FITC image representing specific painted chromosomes, a TRITC image representing the centromeres of all chromosomes, and a DAPI image representing all the counterstained chromosomes. A further algorithm was developed for the automatic classification of the different types of chromosome aberrations, such as translocations, dicentrics, and fragments.

METASIM: object-oriented modelling of cell regulation.

Enzymatic processes and substances are modelled as distinct objects, belonging to a limited number of classes. A set of class definitions in C++ is presented that constitutes an object-oriented programming platform. The latter supports 'biological' data types and functions and facilitates simulation of metabolic and regulatory pathways in living cells.