Acriflavine treatment on Streptomyces tendae generated a bald mutant (bld-1) with an altered antibiotic pattern. The parental strain produced nikkomycins and juglomycins, whereas the mutant bld-1 was only capable of juglomycin synthesis. The existence of a mutant defective in morphogenesis and in nikkomycin biosynthesis suggests a common regulation of these processes. An interesting finding of this study is that mutant bld-1 produced two carbazole derivatives, hitherto never seen in cultures of the parental strain. It seems likely that the DNA intercalating dye acriflavine, by mutagenesis, had activated cryptic genes which are involved in carbazole synthesis. The two carbazole derivatives were identified as the neuronal cell protecting compounds CS-79B and carquinostatin A, recently isolated from a wild-type of S. exfoliatus. We found that both substances showed antibacterial activity.

Acriflavine↗

PubMedDate not supplied

[Anamnestic observation in malignant hypertension].

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Adolescent↗

PubMedDate not supplied

[Experimental study on erysipeloid arthritis in the rabbit after blockage of lymph drainage].

The lymph drainage was radically blocked in 29 rabbits. One to three days after the operation Erysipelothrix rhusiopathiae was inoculated subcutaneously into the animals. Some control animals were injected with agents of erysipelas and some only with the sterile solution without additional blockade of the lymph drainage. Light and electron microscopy as well as immuno-histological tests showed that the erysipelas arthritis developing in rabbits closely resembles human rheumatoid arthritis with exsudative-necrotising changes of the synovial membrane, proliferation of synovial cells and subsynovial, perivascular plasmacell, and lymphocyte infiltration. The changes were not intensified by the additional blockade of the lymph drainage, when comparing the side with lymph drainage blockade and the non-operated side. The results may be explained by a marked pathogenetic importance of the erysipelas infection in comparison to the relatively mild, lymphostate dependent alterations as well as by mobilisation of macrophages on the operated side.

Animals↗