Sir, I was dismayed to see that Phillips et al. were defending what nearly all microbiologists know are grave abuses of antibiotics— their continuous use in feed as growth promoters and the needless widespread use of broad spectrum agents (fluoroquinolones). This is despite their acknowledgement that ‘the more an antibiotic is used, the more likely are resistant populations to develop’ and that...

The maintenance and enhancement of body composition is an energy-dependent process and is impossible without an adequate supply of energy and protein. In certain circumstances, alteration of the normal pattern of protein deposition and metabolism may be considered necessary. Drugs have been used with some success in attaining this end in three distinct clinical areas. First, they are proving ef...

If a monopoly supplies a perishable good, such as tickets to a performance, and is unable to price discriminate within a period, the monopoly may benefit from the potential entry of resellers. If the monopoly attempts to intertemporally price discriminate, the equilibrium in the game among buyers is indeterminate when the resellers are not allowed to enter, and the monopoly’s problem is not wel...

We have developed a procedure for preparing extracts from nuclei of human tissue culture cells that directs accurate transcription initiation in vitro from class II promoters. Conditions of extraction and assay have been optimized for maximum activity using the major late promoter of adenovirus 2. The extract also directs accurate transcription initiation from other adenovirus promoters and cel...

The diterpene tumor promoters enhance the proliferation in culture of myeloid and erythroid precursor cells from normal mouse hemopoietic tissues. The effect is observed only with those diterpenes that are tumor promoters, including 12-O-tetradecanoylphorbol 13-acetate (TPA); diterpenes that are inactive as tumor promoters are ineffective as stimulators of colony formation. Tumor promoters act ...

We show here that the promoters for many of the Escherichia coli ribosomal protein operons are regulated directly by two transcription factors, the small RNA polymerase-binding protein DksA and the nutritional stress-induced nucleotide ppGpp. ppGpp and DksA work together to inhibit transcription initiation from ribosomal protein promoters in vitro and in vivo. The degree of promoter regulation ...