Characterization of Actinomyces isolates from infected root canals of teeth: description of Actinomyces radicidentis sp. nov.

Two strains of a previously undescribed Actinomyces-like bacterium were recovered in pure culture from infected root canals of teeth. Analysis by biochemical testing and polyacrylamide gel electrophoresis of whole-cell proteins indicated that the strains closely resembled each other phenotypically but were distinct from previously described Actinomyces and Arcanobacterium species. Comparative 16S rRNA gene-sequencing studies showed the bacterium to be a hitherto unknown subline within a group of Actinomyces species which includes Actinomyces bovis, the type species of the genus.

Restorative and endodontic results after treatment with cast posts and cores.

Sixty-nine patients who received cast posts and cores in 1978 at the Students' Clinic at the Faculty of Odontology, University of Umeå were recalled for examination in 1984. Fifty-three or 76.8% of the patients with 96 posts and cores or 73.

Oxygen tolerance of anaerobic bacteria isolated from necrotic dental pulps.

The oxygen tolerance of 43 anaerobic reference strains and 36 anaerobic strains from necrotic dental pulps was studied. All strains survived for two hours or more as colonies on the surface of a medium supplemented with blood, and as many as 26 of the 79 strains survived for more than seven days. The hemolysed blood in the medium significantly increased the survival time for many of the strains.

Histone content in relation to amount of heterochromatin and developmental stage in three species of Drosophila.

Relative amounts of various histone fractions in Drosophila chromatin were estimated densitometrically on electrophoretic gel separations. Several consistent and highly significant differences were obtained between larval and adult chromatin. The arginine-rich histones showed the most conspicuous changes: higher amounts of H4 in larvae, higher H3 in adults.