Publications by authors named "Charlene Bierl"

Context.—: As electronic health records (EHRs) become more ubiquitous, physicians have come to expect that laboratory data from a variety of sources will be incorporated into the EHR in a structured format. The Clinical Laboratory Improvement Amendments have standards for data transmission traditionally met by pathologist review of their own hospital laboratory information system transmissions.

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Objectives: Thyroid and rheumatologic autoimmune testing are areas where evidence-based guidance from specialty organizations and Choosing Wisely support utilizing screening tests for autoimmune and thyroid disorders prior to more specialized testing. Adjustment of the orderable options in the electronic health record (EHR) can influence ordering patterns without requiring manual review or additional effort by the clinician.

Methods: The menu was adjusted to reflect recommendations from Choosing Wisely to favor screening tests that automatically reflex to specialized testing on primary care providers' preference lists.

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Objectives: Traditional laboratory utilization measures are unable to detect the results of small-scale utilization improvement efforts in a background of rising patient volumes and acuity. However, accurate assessment is necessary to document effectiveness of these efforts.

Methods: Test menu changes, physician education, and laboratory utilization feedback were used to address costs and overused tests.

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Objectives: We examined the impact of weekly feedback reports on the test-ordering behavior of internal medicine residents.

Study Design: Retrospective analysis of a performance improvement effort.

Methods: In a large, urban, academic medical center, we extracted raw data on every inpatient laboratory test ordered by all internal medicine residents during two 26-week time periods.

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Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD) and glutamate dehydrogenase (GDH) explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways.

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"Multi-stage" search strategies have become widely accepted for peptide identification and are implemented in a number of available software packages. We describe limitations of these strategies for validation and decoy-based statistical analyses and demonstrate these limitations using a set of control sample spectra. We propose a solution that corrects the statistical deficiencies and describe its implementation using the open-source software X!Tandem.

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A classic physiologic response to hypoxia in humans is the up-regulation of the ERYTHROPOIETIN (EPO) gene, which is the central regulator of red blood cell mass. The EPO gene, in turn, is activated by hypoxia inducible factor (HIF). HIF is a transcription factor consisting of an alpha subunit (HIF-alpha) and a beta subunit (HIF-beta).

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We present four patients with late AMR following cardiac transplantation, which was associated with de novo post-transplant anti-HLA class II antibody production. All patients had negative anti-HLA class I and class II antibodies prior to transplantation (as assessed by sensitive Flow PRA bead assays) and had a negative retrospective T- and B-cell flow cytometric cross-match. Upon presentation with late graft rejection due to AMR, all patients were treated with rituximab and serial plasmapheresis with IVIg plus triple-drug immunosuppression therapy.

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Background And Purpose: Plasma glutathione peroxidase (GPx-3) is a major antioxidant enzyme in plasma and the extracellular space that scavenges reactive oxygen species produced during normal metabolism or after oxidative insult. A deficiency of this enzyme increases extracellular oxidant stress, promotes platelet activation, and may promote oxidative posttranslational modification of fibrinogen. We recently identified a haplotype (H(2)) in the GPx-3 gene promoter that increases the risk of arterial ischemic stroke among children and young adults.

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Background And Purpose: Plasma glutathione peroxidase (GPx-3)-deficiency increases extracellular oxidant stress, decreases bioavailable nitric oxide, and promotes platelet activation. The aim of this study is to identify polymorphisms in the GPx-3 gene, examine their relationship to arterial ischemic stroke (AIS) in a large series of children and young adults, and determine their functional molecular consequences.

Methods: We studied the GPx-3 gene promoter from 123 young adults with idiopathic AIS and 123 age- and gender-matched controls by single-stranded conformational polymorphism and sequencing analysis.

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Multiplexed protein analysis using planar microarrays or microbeads is growing in popularity for simultaneous assays of antibodies, cytokines, allergens, drugs and hormones. However, this new assay format presents several new operational issues for the clinical laboratory, such as the quality control of protein-microarray-based assays, the release of unrequested test data and the use of diagnostic algorithms to transform microarray data into diagnostic results.

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Plasma glutathione peroxidase (GPx-3) is a selenocysteine-containing protein with antioxidant properties. GPx-3 deficiency has been associated with cardiovascular disease and stroke. The regulation of GPx-3 expression remains largely uncharacterized, however, and we studied its transcriptional and translational determinants in a cultured cell system.

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Cellular glutathione peroxidase (GPx-1) is the most abundant intracellular isoform of the GPx antioxidant enzyme family. In this study, we hypothesized that GPx-1 deficiency directly induces an increase in vascular oxidant stress, with resulting endothelial dysfunction. We studied vascular function in a murine model of homozygous deficiency of GPx-1 (GPx-1(-/-)).

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Previous in vitro experiments have shown that hyperhomocysteinemia leads to oxidative inactivation of nitric oxide, in part by inhibiting the expression of cellular glutathione peroxidase (GPx-1). To elucidate the role of intracellular redox status on homocysteine-induced endothelial dysfunction and oxidant stress, heterozygous cystathionine beta-synthase-deficient (CBS(-/+)) and wild-type (CBS(+/+)) mice were treated with the cysteine donor L-2-oxothiazolidine-4-carboxylic acid (OTC). CBS(-/+) mice had significantly lower GPx-1 activity compared with their CBS(+/+) littermates, and OTC treatment led to a modest increase in tissue GPx-1 activity and significant increases in total thiols and in reduced glutathione levels in both CBS(+/+) and CBS(-/+) mice.

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