Plants have been proposed as an attractive alternative for pharmaceutical protein production to current mammalian or microbial cell-based systems. Eukaryotic protein processing coupled with reduced production costs and low risk for mammalian pathogen contamination and other impurities have led many to predict that agricultural systems may offer the next wave for pharmaceutical product production. However, for this to become a reality, the quality of products produced at a relevant scale must equal or exceed the predetermined release criteria of identity, purity, potency and safety as required by pharmaceutical regulatory agencies. In this article, the ability of transient plant virus expression systems to produce a wide range of products at high purity and activity is reviewed. The production of different recombinant proteins is described along with comparisons with established standards, including high purity, specific activity and promising preclinical outcomes. Adaptation of transient plant virus systems to large-scale manufacturing formats required development of virus particle and Agrobacterium inoculation methods. One transient plant system case study illustrates the properties of greenhouse and field-produced recombinant aprotinin compared with an US Food and Drug Administration-approved pharmaceutical product and found them to be highly comparable in all properties evaluated. A second transient plant system case study demonstrates a fully functional monoclonal antibody conforming to release specifications. In conclusion, the production capacity of large quantities of recombinant protein offered by transient plant expression systems, coupled with robust downstream purification approaches, offers a promising solution to recombinant protein production that compares favourably to cell-based systems in scale, cost and quality.

The aim of this study is to present a situated measure of empathy where person features such as gender of target and respondent vary within particular social contexts. The Empathy Situation Reaction Scale (ESRS; Manulik, Kelley, White, & Staats, 2004) has good psychometric properties for three different types of situations. Situations were associated with a much larger empathy effect size than gender of respondent. Gender differences on the ESRS were situation dependent, with women reporting more empathy in the social or threat situations than did men but not in situations where the target accidentally caused property damage or loss. The ESRS may be used to assess empathy in complex interactions of situation, target and respondent and provides a model for studying complex social situations.