When antibiotic sensitivity of microorganisms is tested by agar dilution, single antibiotics are incorporated in solid media and 'spot' inocula of test strains are applied to the antibiotic media and to a plate without antibiotic. The usual method of quality control is to include control strains of known sensitivity.1 However, control strains are usually sensitive to a number of antibiotics, an...

The clinical estimation of liver size using radioisotope scintiscans as a standard of reference has been shown to be very inaccurate. The main source of error is in the location of the upper border of the liver. Physical characteristics of the patients influence this measurement.

For examining vitamins, exact quantitations in natural matrices are essential. Up to date, one of the most accurate quantitation methods is the stable isotope dilution assay (SIDA), which is based on the use of isotopically labelled analogues of the analytes as internal standards. The merits of SIDA include the ideal compensation for losses, superior specificity and enhanced sensitivity due to ...

We report on a new, sensitive, and fast LC-MS/MS method for the simultaneous determination of 25 key sphingolipid components in human plasma, including phosphorylated sphinganine and sphingosine, in a single 9-min run. This method enables an effective and high-throughput coverage of the metabolic changes involving the sphingolipidome during physiological or pathological states. The method is ba...

Clinical studies to prevent the development of food allergy have recently helped reshape public policy recommendations on the early introduction of allergenic foods. These trials are also prompting new research, and it is therefore important to address the unique design and analysis challenges of prevention trials. We highlight statistical concepts and give recommendations that clinical researc...

An intramural hematoma is an accumulation of blood between the internal and external elastic membranes within the medial space, whereas an extramural hematoma is a dilution and/or dissemination of blood throughout the adventitia. Intra- and extra-hematomas are observed by intravascular ultrasound during percutaneous coronary intervention (PCI). The patient described herein presented with angina...

In internal and external quality assessment of clinical chemical analyses, the use of reference method values is prescribed in the Federal Republic of Germany as a measure of accuracy control. In the field of lipid analyses, reference methods are available for measuring total cholesterol and total glycerol in control sera. The reference measurement procedures are based on the highly accurate an...