Ping Shen — Page 3 | Search PubMed

PubMedDate not supplied

Yeast transformation process studied by fluorescence labeling technique.

A new method based on fluorescence imaging and flow cytometry was developed to investigate the transformation process of Saccharomyces cerevisiae AY. Yeast and fluorescent-labeled plasmid pUC18 were used as models of cells and DNA molecules, respectively. Binding of DNA molecules to yeast cell surfaces was observed. Factors influencing DNA binding to cell surfaces were investigated. It has been found that poly(ethylene glycol) (PEG) could induce DNA binding to yeast surfaces, while Li(+) showed a weak effect on the binding. When both Li(+) and PEG were used, synergetic effect occurred, resulting in the binding of pUC18 to the surface of more yeast cells compared with that in the presence of PEG or Li(+) only. It was also confirmed that heat shock, Li(+), and PEG all can increase the permeability of yeast cells. This simple method is helpful for understanding the process of yeast transformation and can be used to investigate the interaction of DNA with cell surfaces.

Cell Membrane Permeability↗

PubMedDate not supplied

An analysis of paramedic verbal reports to physicians in the emergency department trauma room.

OBJECTIVE: To measure the verbal communication between emergency medical technician-paramedics (EMT-Ps) and physicians in an emergency department trauma room (EDTR) before and after an educational intervention. METHODS: Using a before-after design, we audio-recorded paramedic verbal trauma reports in a large EDTR over a 12-week period. Trained research assistants subsequently queried physicians about information from the paramedic report in a separate interview. Physician recall was quantified. Midway through the study, a web-based, educational intervention designed to enhance paramedic communication skills was administered to the three participating emergency medical services (EMS) systems. Physician recall of more severely injured trauma cases (red triage) was compared with their recall of less severely injured cases (yellow triage). Further comparisons were made between pre- and post-intervention physician recalls, and the extent to which physicians recalled three distinct categories of paramedic verbal information was measured. RESULTS: Overall, physicians accurately recalled 36% of the paramedic verbal report. Information from less severe "yellow" trauma reports was recalled more accurately than that from more severe "red" traumas (40% vs. 34% p = 0.02). Pre- and post-intervention recalls were not significantly different (33% vs. 38% p = 0.16). Physicians' recall of information about the crash scene (46%) was significantly greater than their recall of information about the patient's health status (34%) or information about prehospital patient care (30%) (p = 0.0012). CONCLUSION: Physicians appear to recall paramedic verbal reports about trauma patients poorly. Recall is probably multifactorial and will require further work to design appropriate interventions.

Emergency Medical Technicians↗