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Darragh A.,LabSource | Snyder M.L.,LabSource | Ptolemy A.S.,Gamma Dynacare Medical Laboratories | Melanson S.,Harvard University
Pain Physician | Year: 2014

Background: Patients treated for chronic pain may frequently undergo urine drug testing to monitor medication compliance and detect undisclosed prescribed or illicit drug use. Due to the increasing use and abuse of benzodiazepines, this class of medications is often included in drug screening panels. However, immunoassay-based methods lack the requisite sensitivity for detecting benzodiazepine use in this population primarily due to their poor cross-reactivity with several major urinary benzodiazepine metabolites. A High Sensitivity Cloned Enzyme Donor Immunoassay (HS-CEDIA), in which betaglucuronidase is added to the reagent, has been shown to perform better than traditional assays, but its performance in patients treated for chronic pain is not well characterized. Objectives: To determine the diagnostic accuracy of HS-CEDIA, as compared to the Cloned Enzyme Donor Immunoassay (CEDIA) and Kinetic Interaction of Microparticles in Solution (KIMS) screening immunoassays and liquid chromatography-tandem mass spectrometry (LC-MS/MS), for monitoring benzodiazepine use in patients treated for chronic pain. Study Design: A study of the diagnostic accuracy of urine benzodiazepine immunoassays. Setting: The study was conducted at an academic tertiary care hospital with a clinical laboratory that performs urine drug testing for monitoring medication compliance in pain management. Methods: A total of 299 urine specimens from patients treated for chronic pain were screened for the presence of benzodiazepines using the HS-CEDIA, CEDIA, and KIMS assays. The sensitivity and specificity of the screening assays were determined using the LC-MS/MS results as the reference method. Results: Of the 299 urine specimens tested, 141 (47%) confirmed positive for one or more of the benzodiazepines/metabolites by LC-MS/MS. All 3 screens were 100% specific with no false-positive results. The CEDIA and KIMS sensitivities were 55% (78/141) and 47% (66/141), respectively. Despite the relatively higher sensitivity of the HS-CEDIA screening assay (78%; 110/141), primarily due to increased detection of lorazepam, it still missed 22% (31/141) of benzodiazepine-positive urines. The KIMS, CEDIA, and HS-CEDIA assays yielded accuracies of 75%, 79%, and 90%, respectively, in comparison with LC-MS/MS. Limitations: This study was limited by its single-site location and the modest size of the urine samples utilized. Conclusions: While the HS-CEDIA provides higher sensitivity than the KIMS and CEDIA assays, it still missed an unacceptably high percentage of benzodiazepine-positive samples from patients treated for chronic pain. LC-MS/MS quantification with enzymatic sample pretreatment offers superior sensitivity and specificity for monitoring benzodiazepines in patients treated for chronic pain. Source

Mcfarlane A.,Laboratory Management Services | Mcfarlane A.,Institute for Quality Management in Healthcare IQMH | Aslan B.,Laboratory Management Services | Aslan B.,Institute for Quality Management in Healthcare IQMH | And 4 more authors.
International Journal of Laboratory Hematology | Year: 2015

Introduction: Critical values are life-threatening results that require immediate notification to the patient's healthcare provider. Accreditation bodies require laboratories to establish critical values. A survey of Ontario laboratories was conducted to determine current practice for critical values in hematology. Methods: The survey was sent to 182 participants questioning sources for establishing critical values, levels, review frequency, delta checks, and reporting. The survey was completed by laboratory managers, supervisors, technical specialists, senior technologists, and bench technologists working in hematology. Results: The majority of participating laboratories have established critical values limits for hemoglobin, leukocyte counts, and platelet counts. Most laboratories also include the presence of malaria parasites and blast cells. Some laboratories reported the presence of plasma cells, sickle cells, schistocytes, and spherocytes as critical values. Multiple sources are used for establishing a critical value policy. There was variability for the frequency of critical values review. Rules may differ for a first-time patient sample vs. a repeat patient sample. Delta checks are seldom used to determine whether a result should be called a critical value. Most participants require the individual taking the critical result(s) to read back and confirm that they are directly involved with the patient's care. Conclusion: There is a lack of consensus for critical values reporting in hematology. As critical value reporting is crucial for patient safety, standardization of this practice would be beneficial. © 2014 John Wiley & Sons Ltd. Source

Bourner G.,Gamma Dynacare Medical Laboratories | De la Salle B.,UK National External Quality Assessment Scheme for General Haematology | George T.,University of New Mexico | Tabe Y.,Juntendo University | And 4 more authors.
International Journal of Laboratory Hematology | Year: 2014

One of the many challenges facing laboratories is the verification of their automated Complete Blood Count cell counters for the enumeration of body fluids. These analyzers offer improved accuracy, precision, and efficiency in performing the enumeration of cells compared with manual methods. A patterns of practice survey was distributed to laboratories that participate in proficiency testing in Ontario, Canada, the United States, the United Kingdom, and Japan to determine the number of laboratories that are testing body fluids on automated analyzers and the performance specifications that were performed. Based on the results of this questionnaire, an International Working Group for the Verification and Performance of Automated Cell Counters for Body Fluids was formed by the International Council for Standardization in Hematology (ICSH) to prepare a set of guidelines to help laboratories plan and execute the verification of their automated cell counters to provide accurate and reliable results for automated body fluid counts. These guidelines were discussed at the ICSH General Assemblies and reviewed by an international panel of experts to achieve further consensus. © 2014 John Wiley & Sons Ltd. Source

Bailey D.,University of Toronto | Bailey D.,Gamma Dynacare Medical Laboratories | Perumal N.,University of Toronto | Al Mahmud A.,International Center for Diarrheal Disease Research | And 4 more authors.
Clinical Biochemistry | Year: 2014

Background: Poor vitamin D status (i.e. low serum 25-hydroxyvitamin D (25(OH)D)) has been associated with adverse clinical outcomes during pregnancy and childhood. However, the interpretation of serum 25(OH)D levels may be complicated by the presence of the C3-epimer of 25(OH)D. We aimed to quantify C3-epi-25(OH)D3 in pregnant women and fetuses, to explore the relationship of the C3-epimer between maternal and cord samples, and to establish whether infant C3-epimer abundance is explained by prenatal formation. Methods: In a sub-study of a randomized trial of prenatal vitamin D3, 25(OH)D3 and C3-epi-25(OH)D3 were quantified by LC-MS/MS in 71 sets of mother-fetus-infant serum samples, including maternal delivery specimens, cord blood, and infant specimens acquired at 3-28weeks of age. Results: Without supplementation, median concentrations of C3-epi-25(OH)D3 were higher in infants (6.80nmol/L) than mothers (0.45nmol/L) and cord blood (0nmol/L). However, there was substantial variation such that C3-epi-25(OH)D3 accounted for up to 11% (maternal), 14% (cord), and 25% (infant) of the total 25(OH)D3. Supplemental vitamin D3 significantly increased maternal-fetal C3-epi-25(OH)D3, and was a preferential source of C3-epi-25(OH)D3 compared to basal vitamin D, possibly due to C3-epi-cholecalciferol in the supplement. Multivariate regression did not suggest transplacental transfer of C3-epi-25(OH)D3, but rather indicated its generation within the fetal-placental unit from maternally-derived 25(OH)D3. Neither maternal nor fetal C3-epi-25(OH)D3 is accounted for the relatively high concentrations of infant C3-epi-25(OH)D3, suggesting rapid postnatal generation. Conclusions: C3-epi-25(OH)D3 is present in some pregnant women and fetuses, but does not appear to be efficiently transferred transplacentally. High C3-epimer concentrations in infancy are probably due to postnatal formation rather than fetal stores. © 2014 The Canadian Society of Clinical Chemists. Source

Abdou Mohamed M.A.,University of Toronto | Abdou Mohamed M.A.,Zagazig University | Raeesi V.,University of Toronto | Turner P.V.,University of Guelph | And 3 more authors.
Biomaterials | Year: 2016

The increasing occurrence of antimicrobial resistance among bacteria is a global problem that requires the development of alternative techniques to eradicate these superbugs. Herein, we used a combination of thermosensitive biocompatible polymer and gold nanorods to specifically deliver, preserve and confine heat to the area of interest. Our data demonstrates that this technique can be used to kill both Gram positive and Gram negative antimicrobial resistant bacteria in vitro. Our approach significantly reduces the antimicrobial resistant bacteria load in experimentally infected wounds by 98% without harming the surrounding tissues. More importantly, this polymer-nanocomposite can be prepared easily and applied to the wounds, can generate heat using a hand-held laser device, is safe for the operator, and does not have any adverse effects on the wound tissue and healing process. © 2016 Elsevier Ltd. Source

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