The correlation of phenylalanine ammonia-lyase and cinnamic acid-hydroxylase activity changes in Jerusalem artichoke tuber tissues

Summary Phenylalanine ammonia-lyase (PAL) and cinnamic acid-hydroxylase (CAH) exhibit parallel activity changes in tissues of Jerusalem artichoke (Helianthus tuberosus L.) tubers during ageing and in vitro culture. The activity of both enzymes appears in the tissue only after slicing and can be stimulated by manganese. Inhibition of CAH, by the deprivation of the substrate O₂, leads to cinnamic acid accumulation and PAL inhibition, a process prevented by cycloheximide. It is propounded that the link between PAL and CAH activities is the result of changes of the cinnamic acid pool size produced by a change in the activity of CAH.     

The technology of the Global HIV Vaccine Research Cryorepository

This paper gives an overview of our developments in the fields of cryotechnology and cryoelectronics for managing biological samples stored over liquid nitrogen, fields that are essential to a central cryostorage facility for AIDS related material used in worldwide collaborative research. As a fundamental part of this project we have developed new electronic cryovials and carrier plates attached to Flash memory chips, so that a redundant and portable set of data is present with each sample. The recovery of peripheral blood mononuclear cells (PBMCs) after cryopreservation in the new cryosubstrates showed, especially for small sample volumes (0.1 ml), an increased viability in comparison to the preservation in standard cryovials. The electronic cryosubstrates interface with a dedicated laboratory workflow management system for reproducible and standardized sample processing. This system can read standard operating procedures (SOPs) stored on each sample's memory chip. Finally, we have developed a polymorphic cryoelectronic infrastructure for sample storage tanks. This cryoelectronic system has been integrated in a hermetic storage and semiautomatic handling environment. The new technologies provide state‐of‐the‐art sample identification, documentation and tracking that brings added value to each sample. The first application of these technologies is in a worldwide collaborative research towards the production of an AIDS vaccine. The functionality and versatility of the technologies will lead to an essential optimization of sample and data exchange for global clinical studies by ensuring a high degree of standardization between laboratories.