Rapid multiparameter analysis of cell stimulation in mixed lymphocyte culture reactions.

A flow-cytofluorometric method, based on the differential stability of deoxyribonucleic acid versus ribonucleic acid with the metachromatic dye, acridine orange, simultaneously measures the following parameters of stimulation in mixed lymphocyte cultures: (a) number of nonstimulated cells; (b) total number of stimulated lymphocytes; (c) number of stimulated lymphocytes in G1, S and G2 + M phases of the cell cycle; (d) number of macrophages; (e) number of dead cells. The progress of lymphocyte stimulation may also be measured by a parameter representing ribonucleic acid accumulation per cell. The method is rapid, avoids cell rinsing, fixation and centrifugation and is applicable to microcultures. Multiparameter analysis of cell stimulation which provides simultaneous measurements of lymphocyte proliferation and accumulation of ribonucleic acid per cell may prove to be a more sensitive assay of histocompatibility than tests based only on cell proliferation (tritiated thymidine incorporation).     

Untersuchungen zur histochemischen Darstellung der Sorbitdehydrogenase

Zusammenfassung Eine histochemische Nachweismethode für das zu den Polyoldehydrogenasen gehörende Sorbit-dehydrierende Enzym wird beschrieben. Insbesondere wird die Abgrenzung gegenüber der NAD-abhängigen Xylitdehydrogenase untersucht, da beide Fermente hinsichtlich ihres Wirkungsbereiches homospezifisch sind. Na-Aedta, das keinen Einfluß auf den histochemischen Nachweis der NAD-Xylitdehydrogenase besitzt, führt zu einer Verzögerung der histochemischen Darstellung der Sorbitdehydrogenase. Außerdem wird die Einwirkung von Natriumborat auf beide Fermentreaktionen untersucht, da diese Substanz biochemisch eine Hemmung der Sorbitdehydrogenase verursacht. Die mögliche Unterscheidung beider Enzyme auf Grund ihres Verhaltens wird erwogen. Abschließend wird die intrazelluläre Verteilung der beiden Polyoldehydrogenasen verglichen.

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Summary A topochemical method is described for the determination of the NAD-linked sorbitol-dehydrating enzyme. Furthermore it is discussed the relation of the sorbitoldehydrogenase to the NAD-linked xylitoldehydrogenase, as both enzymes are homospecific polyoldehydrogenases. Na₂-Edta has no influence on the determination of (NAD)-xylitoldehydrogenase, whereas a marked delay of the sorbitoldehydrogenase reaction is observed. Sodium borate as a biochemical inhibitor of the sorbitoldehydrogenase is also effective in the histochemical reaction and gives the base of a possible distinction between both enzymes. The intracellular distribution of the polyoldehydrogenases is compared.