Transfusion management of trauma from the 2019 El Paso mass shooting incident.

Background And Objectives: Mortality rates, transfusion ratios, trauma management logistics, and assault characteristics from the El Paso mass shooting incident (MSI) are evaluated in comparison to other MSIs. In 2019, El Paso, TX experienced the eighth-deadliest MSIs in modern US history. In this 21st mass killing in the United States of 2019, 19 people died immediately, and four of 27 injured, later died from ballistic injuries.

Hemodynamic Determinants of the Biologic Variation of N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Stable Systolic Chronic Heart Failure.

Background Context: Biologic variation of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in chronic heart failure (CHF) may affect blood levels and risk stratification. The sources of NT-proBNP variation are unknown.

Methods And Results: We performed NT-proBNP measurements and clinical and hemodynamic assessments in 50 patients with heart failure with reduced ejection fraction (HFrEF) who met criteria for clinical stability over 2 time intervals.

PD-1 and PD-L1 expression in bone and soft tissue sarcomas.

PD-1 and its ligands have been shown to play a significant role in evasion of malignant tumour cells from the immune system. Last year, the Unites States Food and Drug Administration (FDA) approved anti-PD-1 inhibitors for treatment of non-small cell lung carcinoma and recently expanded the use of immunotherapy for metastatic urothelial cell carcinoma and Hodgkin lymphoma. However, studies on expression of PD-1 and its ligand in malignant bone and soft tissue sarcoma are sparse.

Enhanced expression of Programmed cell death 1 (PD-1) protein in benign vascular anomalies.

Programmed cell death 1 (PD-1) and its ligands have been shown to play a significant role in evasion of malignant tumour cells from the immune system. Last year, the United States Food and Drug Administration (FDA) approved anti-PD-1 inhibitors for treatment of non-small cell lung carcinoma and recently has approved anti-PD-L1 blocker for treatment of metastatic urothelial cell carcinoma. However, the role that the immune system might have on benign tumours including vascular anomalies has received less attention.

Biological variation of the cardiac index in patients with stable chronic heart failure: inert gas rebreathing compared with impedance cardiography.

Aims: In chronic heart failure (CHF), changes in cardiac function define the course of the disease. The cardiac index (CI) is the most adequate indicator of cardiac function. Interpretation of serial CI measurements, however, requires knowledge of the biological variation of CI.

α-Glutathione S-Transferase: A New Biomarker for Liver Injury?

Background: Serum alanine and aspartate aminotransferases (ALT/AST) have been the gold standard for detection and quantification of liver injury for over 6 decades, but have relatively long half-lives (T½) (literature estimates approximately 17 and 47 h, respectively) and thus do not reflect immediate changes in liver injury or recovery. A new point-of-care immunoassay for α-glutathione S-transferase (α-GST) measures this cytosolic liver enzyme with a predicted T½ of 60-90 min based on preliminary studies and might enable earlier detection of improving or worsening liver injury than conventional enzyme testing.

Methods: Serial serum samples collected daily from 31 patients enrolled in the Acute Liver Failure Study Group, with acetaminophen (APAP) toxicity, drug-induced liver injury, ischemic hepatopathy (IH), or autoimmune hepatitis were analyzed to determine α-GST using the Qualigen FastPack® α-GST Assay (Carlsbad), a chemiluminescent immunoassay using a paramagnetic particle matrix with an upper limit of normal of 11 ng/mL.

Healthcare Cost of Over-Diagnosis of Low-Grade Dysplasia in Barrett's Esophagus.

Introduction: Published reports have demonstrated that many Barrett's esophagus patients are over-diagnosed as low-grade dysplasia (BE-LGD). We performed an analysis of the surveillance and treatment costs associated with the over-diagnosis of BE-LGD.

Methods: As the principal cost variables, we used endoscopic and histologic procedures performed during the recommended surveillance intervals for patients with BE-LGD, the national average Medicare reimbursement for the Current Procedural Terminology codes of the procedures performed, and a spreadsheet-based tool we created to determine the overall healthcare cost associated with the over-diagnosis of BE-LGD in the US population.

Biological variation, reference change value (RCV) and minimal important difference (MID) of inspiratory muscle strength (PImax) in patients with stable chronic heart failure.

Background: Despite the widespread application of measurements of respiratory muscle force (PImax) in clinical trials there is no data on biological variation, reference change value (RCV), or the minimal important difference (MID) for PImax irrespective of the target cohort. We addressed this issue for patients with chronic stable heart failure.

Methods And Results: From the outpatients' clinic of the University of Heidelberg we retrospectively selected three groups of patients with stable systolic chronic heart failure (CHF).

Minimal important difference for 6-minute walk test distances among patients with chronic heart failure.

Background: The 6-minute walk test (6 WT) is an established tool in the assessment of endurance and prognosis in patients with chronic heart failure (CHF). For these patients there is very limited data on biological variation of 6 WT distances. We determined the minimal important difference (MID) for the 6 WT in patients with stable systolic CHF.

Biological variation of galectin-3 and soluble ST2 for chronic heart failure: implication on interpretation of test results.

Background: Galectin-3 and soluble ST2 (sST2) are novel serum biomarkers of chronic heart failure.

Methods And Results: The biological variability of galectin-3 and sST2 was measured from a cohort of 17 healthy subjects where blood was taken once every 2 weeks for 8 weeks (n = 4 samples) and from 12 subjects where blood was taken hourly (for galectin-3 only). The analytical, intraindividual, and interindividual variation were measured for galectin-3 (BG Medicine, Waltham, MA) and sST2 (Critical Diagnostics, San Diego, CA).

Identification of designer drug 2C-E (4-ethyl-2, 5-dimethoxy-phenethylamine) in urine following a drug overdose.

In recent years, access to information regarding acquisition and synthesis of newer designer drugs has been at an all-time high due largely to the Internet. As these drugs have become more prevalent, laboratory techniques have been developed and refined to identify and screen for this burgeoning population of drugs. This provides a unique opportunity for learning about many of these methods.

Long-term biological variation in cardiac troponin I.

Objectives: To determine the long-term biological variation (BV) of cardiac troponin I.

Design And Methods: Three samples separated by a mean of 8.7 ± 2.

Biological variation and reference change value of high-sensitivity troponin T in healthy individuals during short and intermediate follow-up periods.

Background: Acute myocardial infarction is defined by a troponin concentration >99th percentile with an acute increase and/or decrease, the magnitude of which has not yet been well defined. To aid the interpretation of changes in cardiac troponin concentration, we sought to establish biological variation and reference change values (RCVs) by applying both the normal and lognormal approaches for cardiac troponin T (cTnT) sampled at hourly and weekly intervals in healthy individuals and measured on the Roche E 170 and Elecsys® 2010 automated platforms.

Methods: High-sensitivity cTnT (hsTnT) was measured at baseline, and after 1, 2, 3, and 4 h and after 1, 2, 3, and 4 weeks in 20 and 17 healthy individuals, respectively.

Performance evaluation of the new ADVIA Centaur system cyclosporine assay (single-step extraction).

Background: Cyclosporine (CsA) monitoring is essential for transplant success. We report a performance study of the recently released, fully automated Siemens ADVIA Centaur CsA assay.

Methods: Whole blood samples from 248 transplant patients were prepared using a new 1-step extraction method.

Longitudinal studies of cardiac troponin-I concentrations in serum from male Sprague Dawley rats: baseline reference ranges and effects of handling and placebo dosing on biological variability.

Serum cardiac troponin-I has been validated as a biomarker for cardiotoxicity in numerous animal models; however, baseline reference ranges for cTnI concentration in a healthy population of laboratory rats, as well as an investigation of biological cTnI variability in rats with respect to time, handling, and placebo dosing methods, have not been reported. In this study, we used an ultrasensitive cTnI immunoassay to quantify hourly concentrations of cTnI in live rats handled under standard laboratory conditions using 15 microL of serum per determination. The baseline reference range (mean 4.

Rapid cortisol assays improve the success rate of adrenal vein sampling for primary aldosteronism.

Objective: We hypothesized that an adrenal vein sampling (AVS) algorithm incorporating rapid cortisol assays, which enables resampling of the adrenal veins, would improve the success rate by a team of radiologists.

Summary Background Data: AVS is the most accurate means to localize aldosterone production in primary aldosteronism (PA). However, cannulation of the right adrenal vein (RAV) is difficult, and success is assumed from venography without the support of steroid assays.

Short- and long-term biological variation in cardiac troponin I measured with a high-sensitivity assay: implications for clinical practice.

Background: The improved detection limit and precision in new-generation commercial assays for cardiac troponin I (cTnI) have lowered the 99th-percentile cutoff value, yielding higher frequencies of positive test results. Because serial testing is important in interpreting low concentrations, we evaluated the biological variation of cTnI in both the short (hours) and long (weeks) terms and determined reference change values (RCVs) and the index of individuality (II) for cTnI.

Methods: To assess short- and long-term variation, we collected blood from 12 healthy volunteers hourly for 4 h and from 17 healthy individuals once every other week for 8 weeks, measured cTnI with a high-sensitivity assay (detection limit, 0.

Interpretation of creatine kinase and aldolase for statin-induced myopathy: Reliance on serial testing based on biological variation.

Background: Statins are widely used drugs to reduce LDL cholesterol and risk for cardiovascular disease. Varying degrees of myopathies occur with statin use, ranging from mild myalgic symptoms alone to documented muscle damage and rhabdomyolysis. The activity of creatine kinase (CK) above a population-based reference range has been used to differentiate myalgias from documented myositic injury due to statins.

False positive acetaminophen concentrations in patients with liver injury.

Background: Acetaminophen toxicity is the most common form of acute liver failure in the U.S. After acetaminophen overdoses, quantitation of plasma acetaminophen can aid in predicting severity of injury.

Prevalence of cocaine use in ED patients with severe hypertension.

Study Objective: We prospectively evaluated the prevalence of cocaine use in emergency department patients with elevated diastolic blood pressure greater than 120 mm Hg.

Design: Urine was collected on adult patients with diastolic blood pressure greater than 120 mm Hg. The Institutional Review Board granted a waiver of informed consent based on complete deidentification of the data to prevent selection bias.

Measurement of 18-hydroxycorticosterone during adrenal vein sampling for primary aldosteronism.

Context: In primary aldosteronism, elevated serum 18-hydroxycorticosterone (18OHB) suggests aldosterone-producing adenoma (APA) rather than bilateral, idiopathic hyperaldosteronism (IHA), but little is known about the relative production of 18OHB and aldosterone (A) in APAs compared with IHA.

Objectives: We measured 18OHB, A, and cortisol (F) in blood from adrenal vein sampling (AVS) studies. We compared the discriminatory power of gradients in 18OHB/A and 18OHB/F ratios with A/F ratio gradients for distinguishing APA from IHA.

Spurious prostate-specific antigen (PSA) recurrence after radical prostatectomy: interference by human antimouse heterophile antibodies.

Human antimouse heterophile antibodies (HAMA) are naturally occurring antibodies that can interfere with modern serum assays. We report a case of HAMA interference with a commonly used prostate-specific antigen (PSA) assay, leading to false elevation (2.17-2.