Error rates in Australian chemical pathology laboratories.

OBJECTIVE: To measure transcription and analytical errors made by Australian chemical pathology laboratories. DESIGN: Retrospective data collection covering the period 1 November 1993 to 1 April 1994. SETTING AND PARTICIPANTS: Fourteen pathology laboratories in five Australian States (seven in the public sector, and seven in the private sector). MAIN OUTCOME MEASURES: Error rates in transcribing information from request forms to computer record systems, and laboratory performance on chemical analysis. RESULTS: Pathology laboratories had a transcription-error rate of up to 39% and an error rate of up to 26% for analytical results. The worst-performing laboratory had errors (of patient identification or results of analysis) in 46% of requests. The three best-performing laboratories achieved 85% error-free reporting, with one achieving 95%. CONCLUSIONS: Error rates in Australian pathology laboratories vary widely, but may be as high as 46% for all specimens in some laboratories. The types of errors reported were under the control of the laboratory, and would affect the accuracy of reported pathology test results, with potential adverse outcomes for patient care and inefficient use of health-care resources. There is a need to establish broader quality assurance programs and performance requirements to reduce these types of error.

The effect of interposition membrane on the outcome of lumbar laminectomy and discectomy.

STUDY DESIGN: This study evaluated clinical and magnetic resonance imaging differences of patients treated surgically for lumbar disc herniation. Clinical follow-up and magnetic resonance imaging evaluation of epidural fibrosis were used to assess patient outcome. OBJECTIVES: The purpose of this study was to evaluate the difference in clinical outcome with either free-fat graft, Gelfoam, or no interposition membrane placed in the laminectomy defect after nerve root decompression. SUMMARY OF BACKGROUND DATA: Epidural fibrosis has been considered a cause of recurrent symptoms after lumbar laminectomy, and numerous materials have been evaluated for prophylaxis of the "laminectomy membrane." These have been mainly histologic and animal studies with no data correlating clinical symptoms and postoperative epidural scar formation. METHODS: One hundred fifty-six patients who were treated surgically for lumbar disc herniation were randomly assigned to one of three groups and followed prospectively for at least 1 year. Thirty-three of these patients were received magnetic resonance imaging evaluations after 6 months by an independent radiologist who graded the amount of epidural scar formation. The patients were assessed at 1 year and given a rating of excellent, good, fair, or poor, and the scar was graded as none, minimal, or moderate. RESULTS: Although 97% of all patients improved, 83% were rated excellent or good. There were no statistical differences between the three groups clinically and radiographically. Patients with workers compensation had a statistically significant lower success rate (P < 0.001). CONCLUSIONS: Clinical outcome after lumbar disc surgery does not correlate with the use or type of interposition membrane used to prevent epidural fibrosis.

The physical state of osmoregulatory solutes in unicellular algae. A natural-abundance carbon-13 nuclear-magnetic-resonance relaxation study.

Natural-abundance 13C n.m.r. spin-lattice relaxation-time measurements have been carried out on intact cells of the unicellular blue--green alga Synechococcus sp. and the unicellular green alga Dunaliella salina, with the aim of characterizing the environments of the organic osmoregulatory solutes in these salt-tolerant organisms. In Synechococcus sp., all of the major organic osmoregulatory solute, 2-O-alpha-D-glucopyranosylglycerol, is visible in spectra of intact cells. Its rotational motion in the cell is slower by a factor of approx. 2.4 than in aqueous solution, but the molecule is still freely mobile and therefore able to contribute to the osmotic balance. In D. salina, only about 60% of the osmoregulatory solute glycerol is visible in spectra of intact cells. The rotational mobility of this observable fraction is approximately half that found in aqueous solution, but the data also indicate that there is a significant concentration of some paramagnetic species in D. salina which contributes to the overall spin-lattice relaxation of the glycerol carbon atoms. The non-observable fraction, which must correspond to glycerol molecules that have very broad 13C resonances and that are in slow exchange with bulk glycerol, has not been properly characterized as yet, but may represent glycerol in the chloroplast. The implications of these findings in relation to the physical state of the cytoplasm and the mechanism of osmoregulation in these cells are discussed.

Carbon-13 nuclear magnetic resonance study of osmoregulation in a blue-green alga.

The process of osmoregulation in a unicellular blue-green alga, Synechococcus sp., has been studied by natural-abundance carbon-13 nuclear magnetic resonance spectroscopy of intact cells and cell extracts. 2-O-alpha-D-Glucopyranosylglycerol was identified as the major organic osmoregulatory solute. This demonstrates the presence of a major osmoregulatory solute in a blue-green alga and is also an example of an osmoregulatory role for glucosylglycerol.