A High-Throughput Colorimetric Microplate Assay for Determination of Plasma Arginase Activity.

Arginase, an enzyme involved in the urea cycle, is gaining attention as a critical player in numerous chronic pathologies. Additionally, increased activity of this enzyme has been shown to correlate with poor prognosis in a range of cancers. Colorimetric assays that measure the conversion of arginine to ornithine have long been used to determine the activity of arginase. However, this analysis is hindered by a lack of standardization across protocols. Here, we describe in detail a novel revision of the Chinard's colorimetric assay used to determine arginase activity. Dilution series of patient plasma are plotted to form a logistic function, from which activity can be interpolated by comparison to an ornithine standard curve. Inclusion of patient dilution series rather than a single point increases the robustness of the assay. This high-throughput microplate assay analyzes 10 samples per plate to produce highly reproducible results.

Routine analysis and characterization of highly insoluble polycyclic aromatic compounds by direct analysis in real time mass spectrometry (DART).

Direct Analysis in Real Time (DART), is used for the first time for the routine rapid analysis of highly insoluble polycyclic aromatic compounds. Direct analysis of such compounds as solid samples under solvent-free conditions shows that DART is a powerful analytical platform capable of providing high-throughput analysis for these complex samples, requiring no special sample pre-treatment or instrument setup.

Vaccines for persons at high risk due to medical conditions, occupation, environment, or lifestyle, 2003.

The safety and efficacy of current vaccines are reviewed for high-risk populations, such as those with underlying medical conditions or occupational or lifestyle circumstances. The morbidity and mortality from vaccine-preventable diseases are high among persons with underlying medical conditions; thus, influenza and pneumococcal polysaccharide vaccines are recommended for those with cardiac disease, diabetes mellitus, or chronic obstructive pulmonary disease. For the same reasons, influenza vaccine is recommended for pregnant women and for persons with asthma. Health-care workers are at risk for acquiring and transmitting hepatitis B, measles, and influenza; hence, vaccination against these diseases is recommended.

HRMS directly from TLC slides. A powerful tool for rapid analysis of organic mixtures.

High-resolution mass spectra (HRMS) of individual spots on thin-layer chromatography (TLC) slides can now be obtained quickly and easily at atmospheric pressure, with zero sample preparation, using commercially available instrumentation. The method is complementary to GC-mass spectrometry but is not limited to compounds of high volatility and high thermal stability. TLC-HRMS can be used to monitor chemical reactions in real time and has the capacity thereby to accelerate significantly the pace of synthetic organic chemistry.

Measles surveillance in the United States: an overview.

The elimination of endemic measles from the United States has been a national goal since the introduction of measles vaccine, and measles surveillance has been crucial to guide the elimination efforts. The United States surveillance system is geared towards detection of measles virus transmission, rapid discovery of measles outbreaks to facilitate outbreak control, and identification of risk factors for measles. The surveillance system is a passive reporting system that, when activated by a reported case of suspected measles, triggers a search for additional cases around the reported case. Cases are typically reported by health care providers or from schools and day care centers. The sensitivity of the system is increased through reporting and investigation of all suspected measles cases by means of an inclusive case definition (generalized maculopapular rash and fever), and the specificity is increased through laboratory testing for measles of all suspected cases.