Cytogenetic studies in dogs after total body irradiation and allogeneic transfusion with cryopreserved blood mononuclear cells: observations in long-term chimeras.

Cytogenetic studies were performed on two dog groups after total body irradiation and allogeneic transfusion with cryopreserved blood mononuclear cells. The first group of dogs was transfused with unseparated leukocytes and suffered from graft-versus-host disease (GvHD). Cytogenetic studies demonstrated only cells of donor origin in all dogs of this group. The second group of animals was transfused with fraction 2 of a discontinuous albumin gradient. The dogs of this group did not develop GvHD, and the cytogenetic studies showed the presence of a mosaic of cells from donor and recipient origin in all of them. These results suggest that the GvHD may suppress autochthonous regeneration.

[Distribution of haemoglobin content in human red cells, estimated by scanning cytophotometry (author's transl)]. / Hämoglobingehalt und Hämoglobinverteilung in peripheren menschlichen Erythrozyten Untersuchungen mit dem Scanning-Zytophotometer.

Haemoglobin content and surface area of human red cells were estimated using a scanning cytophotometer connected to a computer for registration and analysis of the data. The measurements were carried out on fixed, unstained peripheral blood smears at a wavelength of 414 nm. The scanning can be controlled on the screen in order to detect errors and to eliminate extinctions from other sources than the cell examined. The method allows to demonstrate the topographic quantitative distribution of haemoglobin within the cell, to estimate haemoglobin content and surface area in individual cells and to correlate these values, to establish frequency distributions of the data within cell populations and to calculate various statistical parameters. Results of measurements on normal and abnormal red cells (iron deficiency, haemolytic anaemias) are demonstrated. The method may be used for investigation on red cell pathophysiology and may serve as a basis for image analysis in blood smears. It is too time consuming for direct diagnostic application in clinical practice.

[Cell image analysis on the PDP-12 computer: a software system for processing the image information from a scanning microscope photometer (author's transl)]. / Zellbildanalyse am PDP-12-Rechner: Ein Software-System zur Verarbeitung der Bildinformation eines Scanning-Mikroskop-Photometers.

A system of computer programs is introduced which allows image analyzing of cytological or histological preparations. The software system was especially developed for a microprocessor (PDP-12, Digital Equipment Corporation) which is often implied in connection with microscope photometers (SMP 05, Carl Zeiss). Users need not to know anything about computer programming because the computer gives the necessary orders via CRT-display or printer. The different descriptors as they are available after different cytochemical or histochemical staining procedures are combined to a pattern vector which is to be a numerical equivalent of cell morphology. A novel method in numerically describing the fine structure of cell nuclei is emphasized. Different cell populations are compared by means of a simplified multivariate discrimiatory analysis. All programs are written in assembler language and they are stored on LINC tapes (Digital Equipment Corporation). Copies of system tapes respectively tapes with the source programs are available from the authors on sending of blank magnetic tapes (2,000 blocks marked). Description and print out of individual programs are published in the dissertation cited in References. Changes and additions of the system which have been done mean-while will be summarized, and lateron such summaries are available on request.

[Electronic thrombocyte count from total blood]. / Elektronische Zählung von Thrombozyten aus dem Vollblut

Platelets were simultaneously counted in 52 persons by the conventional method of Cronkite and Brecher and with a new electronic cell volume analyser. The platelet counts estimated by the electronic analyser were 10% lower than that measured with the conventional method. This difference decreased to 1.5% when the same diluent was used for both methods. The described electronic counting method of platelets in whole blood is a simple procedure, which gives well reproducible and exact results.