Clinical Chemistry Podcast

Asthma is a chronic inflammatory lung disease that affects an estimated 300 million people worldwide, including 25 million in the United States. There are currently no definitive diagnostic tests for asthma. Diagnosis is based on history and tests of respiratory function.

Circulating tumor cells are fundamental to the concept of a liquid biopsy for cancer. These cells are shed from the primary tumor and are carried in the blood to remote sites, potentially leading to metastasis formation. Understanding more about this process is critical as tumor metastasis is a leading cause of cancer death. Yet this is challenging as the number of circulating tumor cells in an individual is very small, making them difficult to study in detail. Cell lines derived from circulating tumor cells can be created to overcome this problem. This has been done in colon cancer, for example, and enables researchers to examine molecular and functional differences between the circulating tumor cells and those from the primary tumor. In this way, researchers may further our ability to identify and characterize cells that initiate metastasis and to ultimately develop new therapies to stop them. An original report in the January 2017 issue of Clinical Chemistry describes the differential gene expression between colon cancer cell lines derived from circulating tumor cells and the primary tumor. Dr. Catherine Alix-Panabières is the primary author of this article and joins us for this podcast.

Cannabis and its products are the most widely used illicit drugs world-wide, with the majority of countries currently harboring consumers and producers. Medicalization and legalization of the drug...

Disorders of bone metabolism, most notably osteoporosis, are highly prevalent and predispose to fractures, causing high patient morbidity and mortality.

Monitoring of glycemic control with hemoglobin A1c (A1c) in hemodialysis patients may be compromised by anemia and erythropoietin therapy.

In addition to focusing on the publication of cutting-edge scientific reports, Clinical Chemistry has shown a genuine commitment to education by devoting a substantial portion of its pages to educational articles since 2008.

Every year, commercial testing labs earn millions of dollars from selling the anonymized results of blood, urine, tissue, and other tests with almost no public scrutiny or debate.2 Few outside the industry know anything about this trade, and lab workers are often in the dark as well.

Researchers have developed approaches for the noninvasive prenatal testing of single gene diseases.

Interpretation of serial high-sensitivity cardiac troponin (hs-cTn) measurements for the diagnosis of acute myocardial infarction (AMI) assumes random fluctuation of hs-cTn around an individual's homeostatic set point.

Quantifying the variability of biomarkers is important, as high within-person variability can lead to misclassification of individuals. Short-term variability of important markers of vitamin D metabolism is relatively unknown.

Risk stratification in acute myocardial infarction (MI) remains a clinical challenge.

The development and implementation of sensitive and high-sensitivity cardiac troponin assays has not only expedited the early ruling in and ruling out of acute myocardial infarction, but has also contributed to the identification of patients at risk for myocardial injury with necrosis, as confirmed by the presence of cardiac troponin concentrations above the 99th percentile.

Serial measurements of high-sensitivity troponin are used to rule out acute myocardial infarction (AMI) with an assay specific cutoff at the 99th percentile.

Patients with chest pain comprise a large proportion of emergency presentations and place a major burden on healthcare resources.

Pulmonary embolism (PE) is associated with high all-cause and PE-related mortality and requires individualized management.

Chronic kidney disease (CKD) is common, particularly in those of advanced age.

The role of alcohol in the development of subclinical cardiovascular disease is unclear. We examined the association between alcohol consumption and markers of subclinical cardiac damage and wall stress.

The substantial technological advancements in next-generation sequencing (NGS), combined with dropping costs, have allowed for a swift diffusion of NGS applications in clinical settings.

This is the November2016 issue of Clinical Chemistry, Volume 62, Issue 11.

Measurement of serum cancer antigen 125 (CA125) is the standard approach for epithelial ovarian cancer (EOC) diagnostics and follow-up. However, the clinical specificity is not optimal because increased values are also detected in healthy controls and in benign diseases.

Electrophoretic separation of serum and urine proteins has played a central role in diagnosing and monitoring plasma cell disorders. Despite limitations in resolution and analytical sensitivity, plus the necessity for adjunct methods, protein gel electrophoresis and immunofixation electrophoresis (IFE) remain front-line tests.

Circulating tumor DNA (ctDNA) has emerged as a good candidate for tracking tumor dynamics in different cancer types, potentially avoiding repeated tumor biopsies. Many different genes can be mutated within a tumor, complicating procedures for tumor monitoring, even with highly sensitive next-generation sequencing (NGS) strategies.

Most people perceive pilots who don't fly for the commercial airlines as daredevils who always "fall out of the sky." My acquaintances are genuinely surprised to learn that I, a medical doctor and a clinical chemist, am one of those presumed reckless individuals.

The Ebola outbreak in the fall of 2015 led to emergent responses by hospitals to prepare for potential patients. This included preparedness efforts by laboratories, which was challenging as they was evolving and at times contradicting information about how samples from patients under investigation for Ebola should be handled.

Cardiac troponin is integral in the investigation of acute coronary syndromes. Modern high-sensitivity versions of troponin assays are able to detect very low concentrations and potentially identify disease sooner.

It is no secret that laboratory tests are overordered in the clinical environment; a recent metaanalysis demonstrated that tests are overused by 20.6% on average. The ordering of unnecessary tests on such a massive scale may impact not only direct healthcare costs, but also patient safety, and may lead to unnecessary follow-up investigation and iatrogenic blood loss due to excess phlebotomy. Unfortunately, in large hospitals with high patient volumes, it would be impractical for laboratory directors to evaluate every test individually for appropriateness, and even more difficult to convince providers to change ordering practices. Meeting other evidence-based quality objectives in laboratory ordering is similarly labor-intensive.

Initial detection and reporting by clinical microbiology laboratories is a sentinel marker for foodborne outbreak surveillance systems. Initiation of a public health investigation is reliant on the rapid initial identification of pathogens of interest. Diagnostics for Escherichia coli have evolved to reduce identification turnaround time, incorporating technologies for rapid identification (MALDI-TOF MS) and serogrouping (O157 antiserum or latex agglutination). Reporting of these isolates to a public health agency may initiate further laboratory investigations, such as pulsed-field gel electrophoresis, for confirmation that isolates may be related to a common source (clonal population).

Next generation sequencing is increasingly available in clinical laboratories, enabling the sequencing of more genes for relatively lower costs.

The practice of medicine is not always clear-cut. Healthcare providersare often faced with difficult decisions such as what test to perform on patients, what treatment should be given, and what type of follow-up is needed. Providers have a duty to enhance the wellbeing and minimize harm to their patients.

The basic problem shared by many of the biostatistical methods used in marker research is that they relate numbers to other numbers, rather than to anything that we might care about in the real world.

The role of branched-chain amino acids (BCAAs) in cardiovascular disease (CVD) remains poorly understood. We hypothesized that baseline BCAA concentrations predict future risk of CVD and that a Mediterranean diet (MedDiet) intervention may counteract this effect.

Pneumatic tube systems have become a primary way of automating the transport of clinical specimens in medical centers. These may travel within the floors of a building and also between buildings. Although this provides convenience and speed of transport, the excessive acceleration forces and the prolonged time and distance travelled have been linked to pre-analytical variation including hemolysis of blood specimens. As a result, it has been suggested that users regularly assess the forces encountered in a pneumatic tube system.

Postmarket surveillance is an important monitor of the safety of pharmaceuticals and medical devices after regulatory approval and entry to the market. Although premarket studies are substantial, costs prohibit examination of heterogeneous populations or rare events over long durations.

There are nearly 60,000 community pharmacies in the United States today. In addition to being sources of prescriptions and medications, they're also often a site for wellness visits, vaccinations, acute illness diagnosis and treatment, as well as monitoring of chronic disease. Pharmacies often offer a convenient alternative to physician offices because of their accessible locations and extended service hours. Approximately 18% of pharmacies in the U.S. have CLIA-waived status, which means they can perform any of the approximately 120 CLIA-waived tests. Many pharmacists help patients make drug dosage decisions in specialized centers such as coumadin in diabetes clinics. With pharmacists performing and interpreting more laboratory tests, what does this mean for the clinical laboratory community? Do pharmacists receive the proper training to perform and interpret laboratory tests? And how do we ensure the quality of testing?

Protease neprilysin is known to be responsible for the degradation of natriuretic peptides. A recent heart failure (HF) drug, LCZ696 (EntrestoTM), that combines a neprilysin inhibitor and an angiotensin II receptor inhibitor was suggested to augment circulating B-type natriuretic peptide (BNP) concentrations, making the results of BNP measurements diagnostically ambiguous. Because the main form of measured BNP in HF patients is represented by its uncleaved precursor, proBNP, it is important to know the susceptibility of proBNP to cleavage by neprilysin.

CREB-regulated transcription coactivator 3 (CRTC3) is found in adipocytes, where it may promote obesity through disruption of catecholamine signaling. We wished to assess whether CRTC3 is a soluble protein secreted by adipose tissue, explore whether CRTC3 is detectable and quantifiable in the circulation, and ascertain whether CRTC3 serum concentrations are related to metabolic markers in children.

The analysis of dried blood spots has been used routinely for newborn screening since the early 1970s, and the number of disorders screened has expanded substantially in recent years. However, there is a lack of evidence regarding minimum blood spot quality acceptance criteria for sample analysis.

For many years the determination of a routine lipid profile (total, LDL, and HDL cholesterol and triglycerides) has been done routinely in the clinical laboratory using a blood specimen that is collected in the fasting state.

Primary aldosteronism,also known as Conn's syndrome,is a form of endocrine hypertension that results from excess product of aldosterone by the adrenal glands.

More than 70 million couples worldwide are affected by infertility, with male-factor infertility accounting for about half of the cases. Semen analysis is critical for determining male fertility potential, but conventional testing is costly and complex. Here, we demonstrate a paper-based microfluidic approach to quantify male fertility potential, simultaneously measuring 3 critical semen parameters in 10 min: live and motile sperm concentrations and sperm motility.

Clostridium difficile is the most common cause of healthcare associated infections in the United States and is increasingly recognized as a pathogen in the community. This organism is considered to be one of the most urgent antibiotic resistant threats to public health, and can cause a variety of clinical manifestations ranging from asymptomatic to mild diarrhea, to toxic megacolon, and even death.