The nucleotide sequence of the aadB gene which confers resistance to kanamycin, gentamicin, and tobramycin has been determined. The size of the longest reading frame is 747 bases encoding a protein of predicted size 27,992 daltons. A segment of the aadB gene sequence (including the promoter region) was found upstream of the aadA gene in R538-1 and of the dhfrII gene in R388 and the proposed promoters for these genes coincide with the aadB promoter region. The sequence homology extends upstream to the end of the sequenced regions of R388 and R538-1. Almost perfect homology was also found between the sequences 3'- to the aadB gene and 3'- to the aadA genes of R538-1 and pSa. This segment includes a 59 base element previously found flanking the Tn7 aadA gene. A model is presented for the evolution of this region of the plasmid genomes in which the 59- base element functions as an insertional "hot spot" and the possibility that this region is analogous to the aadA/aadB region of the Tn21- like transposon family is considered.

The frequency of moderate to severe adverse reactions associated with smallpox vaccines currently stockpiled in the US, and the continued threat of bioterrorism have prompted the development of effective vaccines with improved safety profiles. LC16m8, an attenuated, replicating smallpox vaccine derived from the Lister strain of vaccinia, is currently licensed in Japan where it was safely used in over 50,000 children in the 1970s. It has been shown to have markedly less neurotoxicity than unattenuated vaccines in nonclinical studies. LC16m8 is immunogenic after a single dose, and recent studies in two different animal models have demonstrated protective efficacy equivalent to that of the only FDA-licensed smallpox vaccine. This article reviews the history and available scientific literature regarding LC16m8 and provides comparisons to other smallpox vaccines.

Ipilimumab (Yervoy®) is an anti-cytotoxic T-lymphocyte antigen (CTLA)-4 monoclonal antibody that has been approved in the US for the first- or second-line treatment of patients with malignant melanoma. In the EU, it is awaiting approval as second-line therapy for melanoma. Ipilimumab blocks the effects of the negative T-cell regulator CTLA-4, which may in turn augment T-cell responses to tumour cells. Preclinical studies have indicated that antibody blocking of CTLA-4 can lead to potent immune responses. Ipilimumab is also in development as first- and second-line therapy for prostate cancer where it has progressed to phase III clinical trials worldwide, and it is in phase II development for non-small cell lung cancer. Ipilimumab was originated by the University of California, Berkeley, in the US and subsequently licensed to Medarex, which was later acquired by Bristol-Myers Squibb. This article summarizes the milestones in the development of intravenous ipilimumab leading to this first approval. This profile has been extracted from Wolters Kluwer's R&D Insight drug pipeline database. R&D Insight tracks drug development worldwide through the entire development process, from discovery, through pre-clinical and clinical studies to market launch.

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The family of cationic lipid transfection reagents described here demonstrates a modular design that offers potential for the ready synthesis of a wide variety of molecular variants. The key feature of these new molecules is the use of Tris as a linker for joining the hydrophobic domain to a cationic head group. The molecular design offers the opportunity to conveniently synthesise compounds differing in charge, the number and nature of hydrophobic groups in the hydrophobic domain and the characteristics of the spacer between the cationic and hydrophobic moieties. We show that prototype reagents of this design can deliver reporter genes into cultured cells with efficiencies rivaling those of established cationic lipid transfection reagents. A feature of these reagents is that they are not dependent on formulation with a neutral lipid for activity.