Determination of Monensin, Narasin, and Salinomycin in Mineral Premixes, Supplements, and Animal Feeds by Liquid Chromatography and Post-Column Derivatization: Collaborative Study

A liquid chromatographic (LC) method for the analysis of monensin, narasin, and salinomycin in mineral premixes, supplements, and complete animal feeds at medicating and trace levels was collaboratively studied. The method uses methanolwater (90 + 10) extraction with mechanical shaking for 1 h, filtration, and dilution if necessary. Determination of the 3 ionophores is by reversed-phase LC using post-column derivatization with vanillin and detection at 520 nm. Suspect positive trace-level products and medicated feeds containing unexpected ionophores are confirmed by hexane extraction or post-column derivatization with dimethylaminobenzaldehyde (DMAB). Twenty-five test samples of medicated feeds, supplements, and mineral and drug premixes, and 9 test samples for trace-level analysis were sent to 11 collaborators in Bulgaria, Czech Republic, Portugal, France, The Netherlands, United States, and Canada. Acceptable results were received from 10 laboratories. For the medicated complete feeds, supplements, and mineral premixes, RSDr values (within-laboratory repeatability) ranged from 2.5 to 5.2%, RSDR values (among-laboratory reproducibility) ranged from 2.7 to 6.8%, and HorRat values ranged from 0.31 to 1.30. For the drug premixes, the result variability was excessive and HorRat values ranged from 2.27 to 14.1. For the trace-level test samples, all laboratories correctly identified the analytes and did not report any false positives. RSDr values ranged from 1.3 to 9.5%, RSDR values ranged from 5.2 to 13.1%, and HorRat values ranged from 0.4 to 0.97.

The SQUIRE (Standards for QUality Improvement Reporting Excellence) guidelines for quality improvement reporting: explanation and elaboration

As the science of quality improvement in health care advances, the importance of sharing its accomplishments through the published literature increases. Current reporting of improvement work in health care varies widely in both content and quality. It is against this backdrop that a group of stakeholders from a variety of disciplines has created the Standards for QUality Improvement Reporting Excellence, which we refer to as the SQUIRE publication guidelines or SQUIRE statement. The SQUIRE statement consists of a checklist of 19 items that authors need to consider when writing articles that describe formal studies of quality improvement. Most of the items in the checklist are common to all scientific reporting, but virtually all of them have been modified to reflect the unique nature of medical improvement work. This "Explanation and Elaboration" document (E & E) is a companion to the SQUIRE statement. For each item in the SQUIRE guidelines the E & E document provides one or two examples from the published improvement literature, followed by an analysis of the ways in which the example expresses the intent of the guideline item. As with the E & E documents created to accompany other biomedical publication guidelines, the purpose of the SQUIRE E & E document is to assist authors along the path from completion of a quality improvement project to its publication. The SQUIRE statement itself, this E & E document, and additional information about reporting improvement work can be found at http://www.squire-statement.org.

Analysis of a two-channel 2R all-optical regenerator based on a counter-propagating configuration

We report a 2R optical regenerator based on the Self-Phase Modulation and offset filtering technique in a bi-directional architecture for the simultaneous processing of two optical channels at 10 Gb/s within a single highly nonlinear fiber. Whereas excellent mitigation of the interchannel nonlinear crosstalk is experimentally demonstrated, we identify Rayleigh backscattering as the major source of crosstalk and show how it is related to the regenerator parameters and operational settings. Finally, we demonstrate that this crosstalk does not introduce any significant additional penalties as compared to single channel operation.

Quality improvement in chronic illness care: a collaborative approach

BACKGROUND

Despite rapid advances in the clinical and psycho-educational management of diabetes, the quality of care received by the average patient with diabetes remains lackluster. The "collaborative" approach--the Breakthrough Series (BTS; Institute for Healthcare Improvement [IHI]; Boston)--coupled with a Chronic Care Model was used in an effort to improve clinical care of diabetes in 26 health care organizations.

METHODS

Descriptive and pre-post data are presented from 23 health care organizations participating in the 13-month (August 1998-September 1999) BTS to improve diabetes care. The BTS combined the system changes suggested by the chronic care model, rapid cycle improvement, and evidence-based clinical content to assist teams with change efforts. The characteristics of organizations participating in the diabetes BTS, the collaborative process and content, and results of system-level changes are described.

RESULTS

Twenty-three of 26 teams completed participation. Both chart review and self-report data on care processes and clinical outcomes suggested improvement based on changes teams made in the collaborative. Many of the organizations evidencing the largest improvements were community health centers, which had the fewest resources and the most challenged populations.

DISCUSSION

The initial Chronic Illness BTS was sufficiently encouraging that replication and evaluation of the BTS collaborative model is being conducted in more than 50 health care systems for diabetes, congestive heart failure, depression, and asthma. This model represents a feasible method of improving the quality of care across different health care organizations and across multiple chronic illnesses.