The kinetics of ER fusion protein activation in vivo.

Reversibly switchable proteins are powerful tools with which to explore protein function in vitro and in vivo. For example, the activity of many proteins fused to the hormone-binding domain of the modified oestrogen receptor (ER(TAM)) can be regulated by provision or removal of 4-hydroxytamoxifen (4-OHT). Despite the widespread use of ER(TAM) fusions in vivo, inadequate data are available as to the most efficacious routes for systemic tamoxifen delivery. In this study, we have used two well-characterized ER(TAM) fusion proteins, both reversibly activated by 4-OHT, to compare the effectiveness and kinetics of 4-OHT delivery in mice in vivo by either tamoxifen in food or by intraperitoneal injection. Our data indicate that dietary tamoxifen offers an effective, facile and ethically preferable means for long-term activation of ER(TAM) fusion proteins in vivo.

Microbiological investigation on black crusts from open-air stone monuments of Bologna (Italy).

Samples of black crusts taken from open-air stone monuments in Bologna dating back to between the twelfth and the nineteenth century were considered. The microbiological test procedures isolated from a high number of chemoorganotrophic bacteria, each of the samples although it was expected to find chemo-lithotrophic (specially sulfur-oxidizing and nitrifying) bacteria on account of the great amounts of sulphur, carbon, nitrogen dioxides and ammonia in the air. Sporogenous and asporogenous species were found among the isolated bacteria: the first were recognized as Bacillus subtilis, Bacillus brevis, Bacillus licheniformis, Bacillus mycoides and Bacillus megaterium; the latter were Corynebacterium glutamicum, Actinomyces sp., Alcaligenes denitrificans subsp. denitrificans, Flavobacterium breve, Acinetobacter calcoaceticus, Enterobacter cloacae, Pseudomonas stutzeri. These species were differently associated in the samples studied with a frequency of more than sixty-four per cent. This finding leads us to believe that their presence in the black crusts is not occasional, but the result of an ecologically significant process of colonization. Although behavioural tests (solubilization of calcium carbonate, of calcium sulphate and marble dust) did not reveal lithic activity among the bacteria studied, one can presume that their behaviour in nature - as a more or less complex microbial consortium - can be totally different and exert a decomposing action with regard to several minerals, most of them acidify the media in which they develop.