Clinical Chemistry Podcast

Prenatal development involves a series of highly-organized genetic and epigenetic events. Abnormalities in the epigenetic control of developmental processes have been implicated in infertility, spontaneous abortion, intra-uterine growth abnormalities, and numerous post-natal consequences.

Human growth hormone is an important peptide hormone that stimulates growth, cell reproduction, and cell regeneration. Measuring growth hormone in the blood is an important clinical assay, but may be problematic due to heterogeneity of the hormone that may arise from alternative splicing, different post-translational or modifications, oligomerization, formation of complexes, and proteolytic processing. Although standards for growth hormone are available, data from external quality assessment programs show large differences exist between measurement results obtained with different assays.

The collection and transport of dried blood spots has facilitated population screening of newborns worldwide. In the July 2013 issue of Clinical Chemistry, researchers from the Wadsworth Center at the New York State Department of Health in Albany described a convenient technique to extract DNA from these dried blood spots to further expand screening to nucleic acid testing.

Alzheimer's disease is a complex progressive neurodegenerative disease leading to loss of memory and cognitive function, and pathologically characterized by amyloid plaques and tangles that are formed largely by fibular forms of beta-amyloid and hyper-phosphorylated tau proteins. During the past two decades, cumulative molecular and clinical studies have provided the basis for our understanding of the molecular characteristics and progressive pathologic features of these hallmarks.

Measurement of serum thyroglobulin may be complicated by the presence of endogenous anti-thyroglobulin auto-antibodies which have the potential to interfere with immunoassays and cause false negative results.

Approximately 1 million metal-on-metal hip prostheses have been implanted worldwide to alleviate pain, restore hip function and improve overall quality of life.

Low-density lipoprotein cholesterol, a key cardiovascular biomarker is recommended by National Cholesterol Education Program, Adult Treatment Panel Guidelines, for assessing cardiovascular disease risk and for monitoring lipid-lowering therapy; however, some workers believe that the number of circulating LDL particles rather than LDL cholesterol is a strong indicator of future cardiovascular disease events.

Readmissions after hospitalization for heart failure are an increasingly important problem, with a significant number of patients being re-hospitalized within 30 days of discharge.

Chemicals in tobacco smoke may influence vitamin D metabolism and function, and vitamin D itself may modify the carcinogenity of tobacco smoke.

A paper in the May 2013 issue of Clinical Chemistry found that circulating microRNAs were deregulated in severe obesity, and the lead author of that study Dr. Francisco José Ortega from Spain joined us earlier for a separate podcast. That paper was accompanied by an editorial addressing the relevance of circulating microRNAs in plasma. The lead author of that commentary, Dr. Catriona Hilton from the Oxford Centre for Diabetes, Endocrinology, and Metabolism in Oxford, England, joins us today in this podcast.

Recently there has been a large amount of attention on a novel human influenza A virus, the H7N9 strain, that as of May 2013, has so far sickened over 131 people and killed 31 in the People's Republic of China. Because of the potential for pandemic spread, there is a great need for rapid and accurate test for the detection of the virus.

Genomics has the potential to provide important insights into the pathogenesis of obesity. A paper in the May 2013 issue of Clinical Chemistry found that circulating microRNAs were deregulated in severe obesity.

enomic research has been widely expected to transform medicine, but progress is not as rapid as some have expected. In the April 2013 issue of Clinical Chemistry, Ramy Arnaout and his colleagues published a paper regarding the cost and the pace of advances in pharmacogenomics.

Obesity, metabolic syndrome, and diabetes are major public health challenges. Recently, interest has surged regarding the possible role of intestinal microbes as potential contributors to the increased prevalence of these three disorders.

Pheochromocytomas are tumors of the adrenal gland that secrete catecholamine. Closely related tumors called extraadrenal paragangliomas can arise at extraadrenal sites. Catecholamine secretion from these tumors causes headache, perspiration, palpitations and hypertension. If not recognized and treated, pheochromocytoma and extraadrenal paraganglioma can lead to arrhythmias, myocardial infarction, stroke and death.

In resource-limited settings, both access to laboratory diagnostics and to patients' health records can be challenging. In the April 2013 issue of Clinical Chemistry, Dr. Samuel Sia and his colleagues described a low-cost mobile device that combines cellphone and satellite communication technologies along with fluid miniaturization techniques for performing all of the functions of an enzyme-linked immunoassay.

MicroRNAs are present in body fluids and have the potential to serve as disease biomarkers. A study in the April 2013 issue of Clinical Chemistry explored the clinical value of microRNAs in serum and urine as biomarkers for idiopathic childhood nephrotic syndrome. This paper was accompanied by an editorial by Johan Lorenzen and Thomas Thum, both from the Hannover Medical School in Hannover, Germany. They both join us today in this podcast.

Genomic research had been widely expected to transform medicine, but progress has been slower than some have expected. To critics delays represent broken promises and/or a sign that at least some of the money spent on genomic research might have been better spent elsewhere.

In the March 2013 issue of Clinical Chemistry, Dr. Yuan Chen and colleagues of the National Taiwan University demonstrated a new miniaturized device that performs most of the key semen analyses that predict male infertility.

For decades, vitamin D deficiency was thought a thing of the distant past, but recent evidence has associated low vitamin D levels with a number of diseases and conditions. Tobacco smoke chemicals may influence vitamin D metabolism and function, and vitamin D itself may modify the carcinogenicity of tobacco smoke.

Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects cannabis has on driving continue to be debated, making legislation and prosecution difficult.

"More Data, Please!" That's the provocative title of Dr. Keith Baggerly's editorial in the March 2013 issue of Clinical Chemistry. He was commenting on an article appearing in the previous month of the journal by Kenneth Witwer who joined us in a podcast earlier this year, regarding the state of data reporting in microRNA studies.

Mass spectrometry has revolutionized many areas of clinical chemistry, but this technology is not just limited to chemistry. Introduction of MALDI-TOF mass spectrometry into the clinical microbiology laboratory has markedly altered workflow allowing bacterial and fungal colonies to be accurately, rapidly, and inexpensively identified.

Early cancer detection before metastasis in asymptomatic patients is one of the primary objectives of cancer research initiatives. Early detection generally means more opportunities for intervention that ultimately lead to improvements in patient outcomes.