Performance of five different electrospray ionisation sources in conjunction with rapid monolithic column liquid chromatography and fast MS/MS scanning

The performances of five different ESI sources coupled to a polystyrene–divinylbenzene monolithic column were compared in a series of LC‐ESI‐MS/MS analyses of Escherichia coli outer membrane proteins. The sources selected for comparison included two different modifications of the standard electrospray source, a commercial low‐flow sprayer, a stainless steel nanospray needle and a coated glass Picotip. Respective performances were judged on sensitivity and the number and reproducibility of significant protein identifications obtained through the analysis of multiple identical samples. Data quality varied between that of a ground silica capillary, with 160 total protein identifications, the lowest number of high quality peptide hits obtained (3012), and generally peaks of lower intensity; and a stainless steel nanospray needle, which resulted in increased precursor ion abundance, the highest‐quality peptide fragmentation spectra (5414) and greatest number of total protein identifications (259) exhibiting the highest MASCOT scores (average increase in score of 27.5% per identified protein). The data presented show that, despite increased variability in comparative ion intensity, the stainless steel nanospray needle provides the highest overall sensitivity. However, the resulting data were less reproducible in terms of proteins identified in complex mixtures – arguably due to an increased number of high intensity precursor ion candidates.     

Alternatives to hospital care: what are they and who should decide?

OBJECTIVE--To examine potential for alternatives to care in hospitals for acute admissions, and to compare the decisions about these alternatives made by clinicians with different backgrounds. DESIGN--Standardised tool was used to identify patients who could potentially be treated in an alternative form of care. Information about such patients was assessed by three panels of clinicians: general practitioners without experience of general practitioner beds, general practitioners with experience of general practitioner beds, and consultants. SETTING--One hospital for acute admissions in a rural area of the South and West region of England. SUBJECTS--Of 620 patients admitted to specialties of general medicine and care of the elderly, details of 112 were assessed by panels. MAIN OUTCOME MEASURES--Proportion of hospitalised patients who could have received alternative care and identification of most appropriate alternative form of care. RESULTS--Both general practitioner panels estimated that between 51 and 89 of the hospitalised patients could have received alternative care (equivalent to 8-14% of all admissions). Consultants estimated that between 25 and 55 patients could have had alternative care (5.5-9% of all admissions). General practitioner bed and urgent outpatient appointment were the main alternatives chosen by all three panels. CONCLUSION--About 10% of admissions to general hospital might be suitable for alternative forms of care. Doctors with different backgrounds made similar overall assessments of most appropriate forms of care.