Analysis of lymphocytes reactive to histocompatibility antigens. III. Detection of inclusion among allo-reactive lymphocyte populations by specific depletion of reactive cells.

We have used a quantitative titration assay for mixed lymphocyte interactions to determine the additivity of responses of rat lymphocyte populations to simultaneous stimulation with major histocompatibility complex alloantigens from pairs of apparently unrelated rat strains. Our inability to detect strict additive stimulation led us to investigate inclusion among allo-reactive lymphocyte populations. After specific depletion of reactivity to PVG by negative selection through an AO × PVG F₁ hybrid rat, AO thoracic duct lymphocytes showed an asymmetrical loss of reactivity to the unrelated strains DA and F344. We suggest that this differential loss of reactivity probably reflects alloantigen sharing among rat strains which had been previously undetected using other less sensitive techniques for the quantitation of lymphocyte reactivity after specific depletion of allo-reactive cells.     

Preliminary clinical experience with the antiarrhythmic effect of PGF2a

A total dosage up to 1 mg PGF_2a as i.v. infusions of 10–40 μg/min. was investigated on patients with arrhythmias of several kinds. We found therapeutic effects in 5 of 6 patients with constant extrasystoles and in one patient with digitalis - induced partial AV-block respectively. In 3 of 4 patients with acute tachyarrhythmias the results were not convincing, probably due to a dosage not high enough. An increase of the diastolic stimulation threshold usually seen with other antiarrhythmics was not to be observed in 3 patients. The mechanism of action of PGF_2a has not yet been clarified.     

High resolution nuclear magnetic resonance study of base pairing in four purified transfer RNA molecules

The high resolution nuclear magnetic resonance spectra of hydrogen bonded protons in four purified tRNA molecules are reported. From the temperature and concentration dependence it is shown that these resonances arise from intramolecular hydrogen bonds.     

Enzymhistochemische Befunde im subependymalen Glialager während der Entwicklung des Rattenhirns

Zusammenfassung Die prä- bzw. postnatale enzymtopochemische Differenzierung des subependymalen Glialagers in der lateralen Wand des Vorderhornes wurde bei der SpragueDawley-Ratte untersucht. Während der pränatalen Entwicklungsphase des Rattenhirns zeichnet sich die Subependymschicht, beim Nachweis der wichtigsten hydrolytischen und oxydativen Enzyme, im allgemeinen durch eine geringe enzymatische Aktivität aus. Die Ergänzung der enzymatischen Ausstattung dieser Zellschicht erfolgt erst während der postnatalen Hirnentwicklung und zwar in den ersten 2 Lebenswochen. Eine Ausnahme von dieser Regel wurde beim Nachweis der Phosphomonoesterase-I festgestellt, welche in der prä- bzw. perinatalen Entwicklungsphase die höchste Aktivität zeigte. Die erhobenen enzymtopochemischen Befunde deuten darauf hin, daß in der subependymalen Zellschicht eine vom übrigen Hirn vor allem zeitlich abweichende topochemische Differenzierung stattfindet, welche im wesentlichen während der ersten 2 Lebenswochen abgeschlossen ist.

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Enzyme topochemical findings of the subependymal cell layer in the developing rat brain

Summary The pre- and postnatal enzyme topochemical differentiation of the subependymal glial layer of the lateral ventricle was examined in the Sprague-Dawley rat. During the prenatal development phase of the subependymal layer, weak enzymatic activity of the most important hydrolytic and oxidative enzymes is demonstrated. The completion of the enzyme activity of this cell layer follows in the postnatal brain development period, and certainly within the first two weeks of life. An exception to this rule has been found in the case of phosphomonoesterase-I which showed the greatest activity in the pre- and perinatal development phases. The observed enzyme topochemical findings indicate that the subependymal cell layer, in contrast to other parts of the brain, shows temporally deviating topochemical differentiation, which is essentially completed in the first two weeks of life.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (SFB 51).