RNA interference: from gene silencing to gene-specific therapeutics.

In the past 4 years, RNA interference (RNAi) has become widely used as an experimental tool to analyse the function of mammalian genes, both in vitro and in vivo. By harnessing an evolutionary conserved endogenous biological pathway, first identified in plants and lower organisms, double-stranded RNA (dsRNA) reagents are used to bind to and promote the degradation of target RNAs, resulting in knockdown of the expression of specific genes. RNAi can be induced in mammalian cells by the introduction of synthetic double-stranded small interfering RNAs (siRNAs) 21-23 base pairs (bp) in length or by plasmid and viral vector systems that express double-stranded short hairpin RNAs (shRNAs) that are subsequently processed to siRNAs by the cellular machinery.

Heroin diffusion in the mid-Hudson region of New York State.

Aims: Prompted by the history of heroin diffusion in the United States, press reports and building on previous research into retail heroin distribution, ethnographic research was undertaken identifying and describing retail distribution and diffusion of heroin in and into medium- and small-sized towns in the mid-Hudson region of New York State.

Methods: In conjunction with fieldwork, in-depth tape-recorded interviews were conducted with recent admissions (30 days) at 28 different drug treatment facilities located in the region. Interviews were also conducted with drug counselors, narcotic officers, drug treatment administrators and the county commissioners of mental hygiene.