Plant-produced human recombinant erythropoietic growth factors support erythroid differentiation in vitro

Clinically available red blood cells (RBCs) for transfusions are at high demand, but in vitro generation of RBCs from hematopoietic stem cells requires significant quantities of growth factors. Here, we describe the production of four human growth factors: erythropoietin (EPO), stem cell factor (SCF), interleukin 3 (IL-3), and insulin-like growth factor-1 (IGF-1), either as non-fused proteins or as fusions with a carrier molecule (lichenase), in plants, using a Tobacco mosaic virus vector-based transient expression system. All growth factors were purified and their identity was confirmed by western blotting and peptide mapping. The potency of these plant-produced cytokines was assessed using TF1 cell (responsive to EPO, IL-3 and SCF) or MCF-7 cell (responsive to IGF-1) proliferation assays. The biological activity estimated here for the cytokines produced in plants was slightly lower or within the range cited in commercial sources and published literature. By comparing EC50 values of plant-produced cytokines with standards, we have demonstrated that all four plant-produced growth factors stimulated the expansion of umbilical cord blood-derived CD34+ cells and their differentiation toward erythropoietic precursors with the same potency as commercially available growth factors. To the best of our knowledge, this is the first report on the generation of all key bioactive cytokines required for the erythroid development in a cost-effective manner using a plant-based expression system.

Transition of care for hospitalized elderly patients--development of a discharge checklist for hospitalists

BACKGROUND

Discharge from the hospital is a critical transition point in a patient's care. Incomplete handoffs at discharge can lead to adverse events for patients and result in avoidable rehospitalization. Care transitions are especially important for elderly patients and other high-risk patients who have multiple comorbidities. Standardizing the elements of the discharge process may help to address the gaps in quality and safety that occur when patients transition from the hospital to an outpatient setting.

METHODS

The Society of Hospital Medicine's Hospital Quality and Patient Safety committee assembled a panel of care transition researchers, process improvement experts, and hospitalists to review the literature and develop a checklist of processes and elements required for ideal discharge of adult patients. The discharge checklist was presented at the Society of Hospital Medicine's Annual Meeting in April 2005, where it was reviewed and revised by more than 120 practicing hospitalists and hospital-based nurses, case managers, and pharmacists. The final checklist was endorsed by the Society of Hospital Medicine.

RESULTS

The finalized checklist is a comprehensive list of the processes and elements considered necessary for optimal patient handoff at hospital discharge. This checklist focused on medication safety, patient education, and follow-up plans.

CONCLUSIONS

The development of content and process standards for discharge is the first step in improving the handoff of care from the inpatient to the posthospital setting. Refining this checklist for patients with specific diagnoses, in specific age categories, and with specific discharge destinations may further improve information transfer and ultimately affect patient outcomes.

Fasciclin I and II have distinct roles in the development of grasshopper pioneer neurons

We have used a new technique, micro-CALI (chromophore-assisted laser inactivation), to investigate the function of the neural cell adhesion molecules fasciclin I and II in the development of the grasshopper Ti1 neurons. Micro-CALI of fasciclin I results in defasciculation of the Ti1 axons similar to that achieved using large scale CALI (Jay and Keshishian, 1990). The initial point of axon separation corresponds to the site of laser irradiation, and defasciculation always continues distal to this point. Micro-CALI of fasciclin II prevents the initiation of Ti1 axon outgrowth but has no effect on fasciculation. This effect is restricted to a 3 hr interval between cytokinesis and growth cone emergence.