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1.
J Transl Autoimmun ; 2: 100006, 2019 Dec.
Article in English | MEDLINE | ID: mdl-32743496

ABSTRACT

BACKGROUND: Activating autoantibodies (AAb) to adrenergic receptors (AR) have previously been reported in patients with postural tachycardia syndrome (POTS). These AAb may contribute to a final common pathway for overlapping disease processes, reflecting a possible autoimmune contribution to POTS pathophysiology. In prior studies, measurement of AAb activity was inferred from costly, low-throughput, and laborious physiological assays. In the present study, we developed and validated an alternative cell-based bioassay for measuring AAb activity in serum by means of pre-treatment with monoamine oxidase (MAO). METHODS: A total of 37 POTS patients and 61 sex-matched healthy control participants were included. Serum was pre-treated with MAO to remove endogenous catecholamines that could falsely inflate AR activation by AAb. A receptor-transfected cell-based bioassay was used to detect presence of α1AR-AAb and ß1AR-AAb in serum. RESULTS: MAO effectively degraded catecholamines as demonstrated by suppression of norepinephrine-induced α1AR activation in POTS (6.4 â€‹± â€‹0.7 vs. 5.5 â€‹± â€‹0.9; P â€‹= â€‹0.044) and in controls (4.1 â€‹± â€‹0.5 vs. 3.9 â€‹± â€‹0.6; P â€‹= â€‹0.001). Mean activity values were greater in the POTS vs. Controls for α1AR-AAb (6.2 â€‹± â€‹1.2 vs. 5.3 â€‹± â€‹1.0; P â€‹< â€‹0.001) and ß1AR-AAb (5.7 â€‹± â€‹1.8 vs. 4.1 â€‹± â€‹0.9; P â€‹< â€‹0.001). Compared to controls, more POTS patients were positive for α1AR-AAb activity (22% vs 4%; P â€‹= â€‹0.007) and ß1AR-AAb activity (52% vs. 2%; P â€‹< â€‹0.001). CONCLUSIONS: The co-presence of norepinephrine in serum samples can artifactually elevate α1AR and ß1AR activity, which can be avoided by serum pre-treatment with MAO. Using this novel bioassay, we show that POTS patients have increased α1AR-AAb and ß1AR-AAb activity compared to healthy controls in the largest POTS cohort reported to-date.

2.
Breast Cancer Res ; 18(1): 90, 2016 09 08.
Article in English | MEDLINE | ID: mdl-27608715

ABSTRACT

BACKGROUND: microRNAs are promising candidate breast cancer biomarkers due to their cancer-specific expression profiles. However, efforts to develop circulating breast cancer biomarkers are challenged by the heterogeneity of microRNAs in the blood. To overcome this challenge, we aimed to develop a molecular profile of microRNAs specifically secreted from breast cancer cells. Our first step towards this direction relates to capturing and analyzing the contents of exosomes, which are small secretory vesicles that selectively encapsulate microRNAs indicative of their cell of origin. To our knowledge, circulating exosome microRNAs have not been well-evaluated as biomarkers for breast cancer diagnosis or monitoring. METHODS: Exosomes were collected from the conditioned media of human breast cancer cell lines, mouse plasma of patient-derived orthotopic xenograft models (PDX), and human plasma samples. Exosomes were verified by electron microscopy, nanoparticle tracking analysis, and western blot. Cellular and exosome microRNAs from breast cancer cell lines were profiled by next-generation small RNA sequencing. Plasma exosome microRNA expression was analyzed by qRT-PCR analysis. RESULTS: Small RNA sequencing and qRT-PCR analysis showed that several microRNAs are selectively encapsulated or highly enriched in breast cancer exosomes. Importantly, the selectively enriched exosome microRNA, human miR-1246, was detected at significantly higher levels in exosomes isolated from PDX mouse plasma, indicating that tumor exosome microRNAs are released into the circulation and can serve as plasma biomarkers for breast cancer. This observation was extended to human plasma samples where miR-1246 and miR-21 were detected at significantly higher levels in the plasma exosomes of 16 patients with breast cancer as compared to the plasma exosomes of healthy control subjects. Receiver operating characteristic curve analysis indicated that the combination of plasma exosome miR-1246 and miR-21 is a better indicator of breast cancer than their individual levels. CONCLUSIONS: Our results demonstrate that certain microRNA species, such as miR-21 and miR-1246, are selectively enriched in human breast cancer exosomes and significantly elevated in the plasma of patients with breast cancer. These findings indicate a potential new strategy to selectively analyze plasma breast cancer microRNAs indicative of the presence of breast cancer.


Subject(s)
Biomarkers, Tumor , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Exosomes/genetics , Exosomes/metabolism , MicroRNAs/genetics , Aged , Aged, 80 and over , Animals , Breast Neoplasms/blood , Breast Neoplasms/pathology , Case-Control Studies , Cell Line, Tumor , Culture Media, Conditioned/metabolism , Disease Models, Animal , Female , Gene Expression Profiling , Heterografts , Humans , Mice , Middle Aged , Neoplasm Grading , Neoplasm Staging , ROC Curve
3.
Clin Lab Med ; 36(1): 183-97, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26851672

ABSTRACT

This article presents an overview of the curriculum deemed essential for trainees in pathology, with mapping to the Milestones competency statements. The means by which these competencies desired for pathology graduates, and ultimately practitioners, can best be achieved is discussed. The value of case (problem)-based learning in this realm, in particular the kind of integrative experience associated with hands-on projects, to both cement knowledge gained in the lecture hall or online and to expand competency is emphasized.

4.
Clin Biochem ; 49(6): 480-485, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26656641

ABSTRACT

OBJECTIVES: Enzymatic activity of lipoprotein-associated phospholipase A2 (Lp-PLA2) mediates vascular inflammation in coronary heart disease (CHD). Calibration of Lp-PLA2 activity measurements using a recombinant enzyme was performed to assess intra- and inter-laboratory assay precision and accuracy in routine clinical settings. DESIGN AND METHODS: Test performance assessment included recovery, analytical sensitivity, linear range, within-lab and site-to-site precision, interference, and analyte stability. Results using the Beckman-Coulter AU400 analyzer were compared to other chemistry analyzers. RESULTS: Lp-PLA2 activity ranged from 84 to 303nmol/min/mL in 300 subjects, with 82.0% and 18.0% measurements below and at or above a cut-point of 225nmol/min/mL, respectively. Results of matched K2-EDTA plasma and serum (n=131) were similar with a slope of 1.00, y-intercept of 0.05, and R-value of 0.988. Mean recovery ranged from 90 to 106% of baseline after storage at different temperatures and time periods. Limit of detection was ≤10nmol/min/mL, without deviation from linearity between 10 and 382nmol/min/mL. Endogenous substances and medications did not interfere with the activity measurements. Overall intra- and inter-laboratory precision among three sites showed coefficients of variation of ≤3.8% and ≤5% respectively. Limit of quantitation was 1.3nmol/min/mL. Method comparison studies for multiple analyzers demonstrated slopes, intercepts or R(2) coefficients ranging from 0.96 to 1.06, -5.6 to 2.0, or 0.997 to 0.999, respectively. CONCLUSION: Analytical performance of the calibrated PLAC(®) test for Lp-PLA2 enzyme activity assay in CHD is resistant to a wide variety of pre-analytical factors, with site-to-site reproducibility on multiple analyzers sufficient to standardize results in diverse laboratory settings.


Subject(s)
1-Alkyl-2-acetylglycerophosphocholine Esterase/metabolism , Calibration , Humans , Limit of Detection , Recombinant Proteins/metabolism , Reproducibility of Results
6.
Surg Pathol Clin ; 8(2): 289-300, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26065801

ABSTRACT

This article presents an overview of the curriculum deemed essential for trainees in pathology, with mapping to the Milestones competency statements. The means by which these competencies desired for pathology graduates, and ultimately practitioners, can best be achieved is discussed. The value of case (problem)-based learning in this realm, in particular the kind of integrative experience associated with hands-on projects, to both cement knowledge gained in the lecture hall or online and to expand competency is emphasized.


Subject(s)
Curriculum , Medical Informatics/education , Pathology, Surgical/education , Clinical Competence , Clinical Laboratory Information Systems , Humans , Problem-Based Learning , United States
7.
Lab Med ; 45(3): 259-63, 2014.
Article in English | MEDLINE | ID: mdl-25051080

ABSTRACT

We report a case of a false-positive HIV result in an apparently healthy pregnant woman. Since no prenatal HIV testing had been performed, we screened for HIV reactivity utilizing the Architect HIV-Ag/Ab Combo assay. Results obtained were inconsistent in that they were repeatedly HIV reactive on a single serum sample while nonreactive on a plasma sample. However, both sample types were nonreactive on the Advia Centaur HIV-1/O/2 and Oraquick assays. For further confirmation, an HIV-1 Western blot and viral load were performed; blot results were indeterminate while the viral load was undetectable. We concluded that the repeatedly reactive serum serology results were false-positive. While the cause of this false reactivity is not clear, most likely fibrin microclots in the serum sample interfered with the assay and thus accounted for the false positivity. Plasma may thus provide a more appropriate sample type when using the Architect assay, especially when testing pregnant women.


Subject(s)
HIV Infections/diagnosis , Pregnancy Complications, Infectious/diagnosis , Adult , False Positive Reactions , Female , HIV Infections/complications , Humans , Pregnancy , Young Adult
8.
Clin Lab Med ; 34(1): 75-85, vi, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24507788

ABSTRACT

Delays in diagnosis and treatment of cardiac patients presenting in the Emergency Department with symptoms of acute coronary syndromes are associated with poorer patient outcomes; hence, the timely and accurate diagnosis in the Emergency Department now requires the 24/7 availability of real-time, rapid testing for cardiac markers. Cardiac troponin (cTnI) has emerged as the biomarker of choice to aid physicians in the diagnosis of acute myocardial infarction and moreover current guidelines call for cTnI results to be available to clinicians within 60 minutes of blood draw each and every time a cTnI is ordered.


Subject(s)
Acute Coronary Syndrome/diagnosis , Emergency Service, Hospital , Troponin/blood , Biomarkers/blood , Chest Pain/complications , Humans , Myocardial Infarction/diagnosis , Point-of-Care Systems , Time Factors , Triage
9.
Bioanalysis ; 5(16): 1953-62, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23937129

ABSTRACT

Bioanalysis invited a selection of leading researchers to express their views on automation in the bioanalytical laboratory. The topics discussed include the challenges that the modern bioanalyst faces when integrating automation into existing drug-development processes, the impact of automation and how they envision the modern bioanalytical laboratory changing in the near future. Their enlightening responses provide a valuable insight into the impact of automation and the future of the constantly evolving bioanalytical laboratory.


Subject(s)
Automation , Biological Assay/methods , Drug Discovery , Laboratories
10.
Am J Clin Pathol ; 140(2): 193-202, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23897254

ABSTRACT

OBJECTIVES: To develop a fully automated core laboratory, handling samples on a "first in, first out" real-time basis with Lean/Six Sigma management tools. METHODS: Our primary goal was to provide services to critical care areas, eliminating turnaround time outlier percentage (TAT-OP) as a factor in patient length of stay (LOS). A secondary goal was to achieve a better laboratory return on investment. RESULTS: In 2011, we reached our primary goal when we calculated the TAT-OP distribution and found we had achieved a Six Sigma level of performance, ensuring that our laboratory service can be essentially eliminated as a factor in emergency department patient LOS. We also measured return on investment, showing a productivity improvement of 35%, keeping pace with our increased testing volume. CONCLUSIONS: As a result of our Lean process improvements and Six Sigma initiatives, in part through (1) strategic deployment of point-of-care testing and (2) core laboratory total automation with robotics, middleware, and expert system technology, physicians and nurses at the Oklahoma University Medical Center can more effectively deliver lifesaving health care using evidence-based protocols that depend heavily on "on time, every time" laboratory services.


Subject(s)
Emergency Service, Hospital/organization & administration , Laboratories, Hospital/standards , Quality Assurance, Health Care , Humans , Laboratories, Hospital/organization & administration , Length of Stay , Software
11.
Am J Clin Pathol ; 129(5): 788-95, 2008 May.
Article in English | MEDLINE | ID: mdl-18426740

ABSTRACT

We compared a rapid, point-of-care multimarker protocol with a single and serial troponin I (TnI)-only protocol in 5,244 patients admitted to the emergency department with chest pain. The diagnosis of acute myocardial infarction (AMI) was based on a doubling myoglobin level accompanied by at least a 50% increase in the creatine kinase (CK)-MB level with no detectable TnI; a doubling of myoglobin level together with any detectable TnI; or a TnI level of 0.4 ng/mL (0.4 microg/L) or more, irrespective of myoglobin or CK-MB results. By using these new criteria, 145 of 148 cases were positive for AMI (positive predictive value [PPV], 92.4%) and 3 were negative, which were also negative by the core laboratory TnI assay. Twelve confirmed non-AMI cases were positive by the new protocol, with 10 of 12 confirmed by the core laboratory as positive for TnI. The negative predictive value (NPV) was 99.9% the overall diagnostic accuracy was 99.7%. The TnI-only protocol had a sensitivity of 68.2% with an NPV of 99.1%. With lower TnI-only cutoffs, 4 patients had false-negative results, and a PPV of 36.4% was observed. Our rapid multimarker protocol seems superior to a TnI-only approach for rapidly triaging patients with chest pain or AMI.


Subject(s)
Biomarkers/blood , Chest Pain/diagnosis , Emergency Medical Services/methods , Myocardial Infarction/blood , Myocardial Infarction/diagnosis , Point-of-Care Systems , Algorithms , Chest Pain/etiology , Creatine Kinase/blood , Female , Humans , Length of Stay , Male , Middle Aged , Myocardial Infarction/complications , Myoglobin/blood , Sensitivity and Specificity , Treatment Outcome , Troponin I/blood
12.
Am J Med Sci ; 333(6): 333-9, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17570985

ABSTRACT

BACKGROUND: Glucosamine is used to treat osteoarthritis. In animals, the compound is known to cause insulin resistance, the underlying abnormality in type 2 diabetes mellitus. Insulin resistance in humans taking oral glucosamine in doses used for osteoarthritis has not been studied. METHODS: Volunteer human subjects (n = 38) without known abnormality of glucose homeostasis had fasting serum glucose, insulin, and lipids determined before and after taking 1500 mg glucosamine by mouth every day for 6 weeks. Fasting insulin and glucose were used to calculate homeostasis model assessment (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI). Vascular elasticity was measured by pulse wave analysis. The paired Student's t test was used to compare baseline with posttreatment values. Pearson's correlation was used to determine the relation of baseline HOMA-IR with changes in other variables. RESULTS: We found a rise in HOMA-IR after 6 weeks of glucosamine (2.8 versus 3.2, P < 0.04). The fall in HOMA-IR among the subjects was statistically related to a higher baseline HOMA-IR by Pearson's correlation(P < 0.01). A rise in serum triglycerides and a rise in LDL cholesterol were statistically related to baseline HOMA-IR. Small artery elasticity fell, and the decrease was higher in those with the highest baseline HOMA-IR. CONCLUSIONS: Notwithstanding its efficacy remaining in question, glucosamine is widely used as treatment for osteoarthritis, which is a condition associated with both obesity and type 2 diabetes mellitus. Our data indicate that persons with underlying poorer insulin sensitivity are at risk for worsening insulin resistance and vascular function with the use of glucosamine in doses used to treat osteoarthritis.


Subject(s)
Glucosamine/administration & dosage , Insulin Resistance , Osteoarthritis/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Arteries/metabolism , Blood Glucose/metabolism , Cholesterol/blood , Female , Glucosamine/adverse effects , Glucosamine/pharmacology , Glucosamine/therapeutic use , Homeostasis , Humans , Lipoproteins, LDL/blood , Male , Middle Aged , Triglycerides/blood
13.
Am J Clin Pathol ; 125(5): 765-70, 2006 May.
Article in English | MEDLINE | ID: mdl-16707380

ABSTRACT

We obtained data on laboratory turnaround time (TAT) and emergency department (ED) length of stay (LOS). We correlated potassium test TAT outlier percentage (TAT-OP) with ED LOS and found that for each outlier percentage (potassium result > 40 minutes), a projected impact on ED LOS was approximately 2.8 additional minutes (ED LOS = 2.79 TAT-OP + 78.77). To address this issue, we began implementation of a totally automated chemistry system to decrease TAT-OPs. Our TAT means did not change substantially with automation (potassium, 28 to 27 minutes); however, TAT-OPs decreased substantially (potassium, 18% to 5%). Preautomation average ED LOS correlated best with the TAT-OP (r(2) = 0.98; P = .01), but this relationship weakened substantially after automation (r(2) = 0.29; P > .05), suggesting the laboratory was no longer a factor in ED LOS. The postautomation ED LOS correlated best with ED patient volume (r(2) = 0.88; P = .06). Although laboratories have focused on TAT means for performance assessment, our study suggests TAT-OPs are more clinically relevant benchmarks. Furthermore, our findings suggest that total laboratory automation can effectively improve overall laboratory service reliability and help eliminate the laboratory as a factor in ED LOS.


Subject(s)
Autoanalysis , Clinical Laboratory Techniques , Emergency Medical Services , Emergency Service, Hospital/organization & administration , Pathology, Clinical , Humans , Length of Stay , Reproducibility of Results , Robotics
16.
Am J Clin Pathol ; 124(5): 672-4, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16203280

ABSTRACT

Poor core laboratory performance that causes delays in diagnosis and treatment is an impediment to optimal patient care, particularly in high-volume patient care areas such as the emergency department (ED). To evaluate the impact of laboratory performance on patient care outcomes, we obtained data from 11 hospitals related to laboratory test turnaround time (TAT) parameters and ED patient throughput. We observed that the average length of stay (LOS) in the ED correlated significantly with the percentage of total laboratory outliers (R2 = 0.75; P < .01) and to a lesser extent the TAT means (R2 = 0.66; P < .01). Furthermore, improvements in laboratory performance during the study were associated with concurrent decreases in ED LOS. Although in the past, laboratories have focused on TAT means for performance assessment, our observations suggest that a more appropriate method of benchmarking might be to aggressively set clinically driven TAT targets and assess performance as the percentage of results achieving this goal.


Subject(s)
Emergency Service, Hospital , Laboratories, Hospital , Length of Stay , Time Management , Clinical Laboratory Techniques , Humans
17.
Otolaryngol Head Neck Surg ; 131(5): 610-5, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15523435

ABSTRACT

OBJECTIVE: To analyze patients with "normal" baseline quick intraoperative parathyroid hormone (QPTH) levels during parathyroidectomy and to determine the prevalence of this finding, the usefulness of the assay in this situation, and to explain the possible causes for this phenomenon. STUDY DESIGN AND SETTING: Patients who underwent parathyroidectomy using QPTH in a tertiary hospital. METHODS: Retrospective analysis of 39 patients treated surgically for primary hyperparathyroidism using QPTH. RESULTS: Of the patients, 14 (36%) had normal baseline QPTH. 8 patients with localizing sestamibi scans had a single adenoma, and excision resulted in a mean decrease of 85.4% in QPTH. Six patients had nonlocalizing sestamibi scans, 1 patient had an 84% drop in QPTH level after removal of a single adenoma, and 5 patients had hyperplasia requiring > or =3 glands excision. At 11.36 months' mean follow-up, 13 patients (93%) were normocalcemic. CONCLUSIONS: A "normal" baseline QPTH level was found in 36% of patients. A 50% decrease in QPTH remains predictive of biochemical cures in patients with localizing sestamibi scans. The likely explanation for this variability in "normal" levels between different assays is the variability in detection of the 7-84 PTH fragment, which results in an overestimation of the PTH level. Assays such as the QPTH, which are more sensitive for the biologically active PTH molecule [(1-84) PTH] than other laboratory PTH assays will tend to have lower PTH levels that can be within the normal range. EBM RATING: B-3.


Subject(s)
Hyperparathyroidism/blood , Parathyroid Hormone/blood , Parathyroidectomy/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Hyperparathyroidism/surgery , Immunoassay/methods , Intraoperative Period , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies
18.
Clin Chem ; 48(12): 2242-7, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12446483

ABSTRACT

BACKGROUND: The stability and stoichiometric changes of analytes in plasma and serum after prolonged contact with blood cells in uncentrifuged Vacutainer tubes were studied. METHODS: We simultaneously investigated the stability of 24 analytes (a) after prolonged contact of plasma and serum with blood cells and (b) after immediate separation of plasma and serum (centrifuged twice at 2000g for 5 min). We verified biochemical mechanisms of observed analyte change by concomitant measurement of pH, PCO(2), and PO(2). Hemolysis was qualitatively and semiquantitatively assessed. All specimens were maintained at room temperature (25 degrees C) and analyzed in duplicate 0.5, 4, 8, 16, 24, 32, 40, 48, and 56 h after collection. Statistically significant changes from the 0.5 h mean were determined using repeated-measures ANOVA. The significant change limit was applied to determine clinically significant changes in measured analytes. RESULTS: Fifteen of 24 analytes in plasma and serum maintained in contact with cells showed clinically relevant changes, with the degree of change more pronounced in most plasma specimens. All analytes in plasma and serum immediately separated from cells after collection were stable. CONCLUSION: Storage of uncentrifuged specimens beyond 24 h caused significant changes in most analytes investigated because of (a) glucose depletion and Na(+),K(+)-ATPase pump failure; (b) the movement of water into cells, causing hemoconcentration; and (c) leakage of intracellular constituents and metabolites. Immediate separation of plasma or serum from cells provides optimal analyte stability at room temperature. When prolonged contact of plasma or serum with cells is unavoidable, use of serum is recommended because of the higher instability of plasma analytes.


Subject(s)
Blood Specimen Collection/methods , Blood Cells , Blood Specimen Collection/instrumentation , Humans , Plasma , Time Factors
19.
EJIFCC ; 12(4): 96-104, 2000 Dec.
Article in English | MEDLINE | ID: mdl-30479591

ABSTRACT

Laboratory medicine is undergoing tremendous change in recent years driven primarily by technology, regulations, reimbursement, and market forces. In this paradigm shift, the laboratory is under tremendous pressure to adapt to new requirements for critical care testing. Indeed, laboratories have entered the information age where chemical data is being extracted from specimens in totally automated fashion. In the past, laboratory data has played a more historical role in the care of critically ill patients, arriving at the bedside too late to be of significant use in the active, ongoing care of the patient. However, today's physicians taking care of critically ill patients now require that laboratory results are made available in real-time and, if possible, at the patient's pont-of-care. Many new testing point-of-care testing devices have been developed to address this need however often laboratories implement such distributed devices with little or no attention to the information technology requirements. In fact, as little as 10 percent of point-of-care testing is actually managed by the central laboratory computer hence critically importance results are not found on the patient's electronic medical record. In addition, the billing and management data for point-of-care testing is often handled manually with no plans to interface point-of-care devices to the laboratory billing and management systems. Because of recent improvements of information handling and interface capability, such shortcomings in data management are no longer acceptable. Indeed, the demands for laboratories to utilize information technology are such that those laboratories with no overall plan for data management of critical care testing will probably not survive this market driven paradigm. We present a discussion of the various approaches to computerization of point-of-care testing including the advantages and the disadvantages of each approach.

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