Intercrossing of phage genomes in a phage cocktail and stable coexistence with Escherichia coli O157:H7 in anaerobic continuous culture.

The emergence of phage-resistant cells is the most serious problem for realizing phage therapy and is observed frequently if only one phage strain is used against a particular bacterium. By contrast, using multiple phages (phage cocktail) can delay or control the appearance of phage-resistant cells. Anaerobic continuous culturing of Escherichia coli O157:H7 and a cocktail of EP16, PP17, and SP22 phages were conducted.

[Five cases of erythema infectiosum in adults].

The similarities between clinical features of erythema infectiosum and collagen disease or other viral infections prompted us to investigate clinical manifestations and laboratory data of parvovirus B19 (B19) infection in adults. We diagnosed all five patients as acute B19 infection by antibody assays. The age of patients ranged from 18 to 39 years old (mean 29), and all patients were female.

The thickness of the sound and periodontally diseased human cementum.

Cementum of teeth previously analysed for fluoride was re-examined in order to determine whether or not periodontal disease had affected the thickness of the tissue. In the periodontally diseased teeth the cementum was thinner than normal in the middle region of the root. The apical cementum, however, was significantly thicker in periodontally diseased than in the sound teeth of subjects over 60 yr old.

Distribution of fluoride in sound and periodontally diseased human cementum.

Fluoride distribution was investigated by an abrasive micro-sampling technique. The fluoride concentration increased with age in both sound and diseased cementum. In sound teeth, the fluoride profiles (distribution of fluoride from the surface to interior) of the middle and apical cementum were similar.