Bead-based microfluidic immunoassay for diagnosis of Johne's disease.

Microfluidics technology offers a platform for development of point-of-care diagnostic devices for various infectious diseases. In this study, we examined whether serodiagnosis of Johne's disease (JD) can be conducted in a bead-based microfluidic assay system. Magnetic micro-beads were coated with antigens of the causative agent of JD, Mycobacterium avium subsp.

A multicenter comparison of established and emerging cardiac biomarkers for the diagnostic evaluation of chest pain in the emergency department.

Background: The aim of this study is to assess the role of novel biomarkers for the diagnostic evaluation of acute coronary syndrome (ACS).

Methods: Among 318 patients presenting to an emergency department with acute chest discomfort, we evaluated the diagnostic value of 5 candidate biomarkers (amino terminal pro-B-type natriuretic peptide [NT-proBNP], ischemia modified albumin, heart fatty acid binding protein, high-sensitivity troponin I [hsTnI], and unbound free fatty acids [FFAu]) for detecting ACS, comparing their results with that of conventional troponin T (cTnT).

Results: Sixty-two subjects (19.

Can exercise-induced changes in B-type natriuretic peptides be used to detect cardiac ischemia?

Background: We reviewed the current medical literature that pertained to the question of whether myocardial ischemia triggers the release of B-type natriuretic peptides (BNPs) and, in particular, whether transient exercise-induced ischemia can be detected by the measurement of changes in these biomarkers. BNPs are well-established as markers of left ventricular dysfunction, particularly heart failure. There is accumulating evidence that various conditions with the common denominator of myocardial ischemia are also associated with increased circulating levels of these peptides.

Stacking due to ionic transport number mismatch during sample sweeping on microchips.

Sample stacking can occur in isoconductive buffer systems as a result of ion transport mismatches that cause changes in buffer conductivity during electrophoresis. Fluorescence imaging was used to examine this effect in the sweeping of hydrophobic dyes with sodium dodecyl sulfate (SDS) on microchips. Imaging revealed the occurrence of a stacking effect in a sodium borate buffer system in which the sample buffer and SDS-containing run buffer had the same initial conductivity.

Preconcentration of proteins on microfluidic devices using porous silica membranes.

Fluorescently labeled proteins were electrophoretically concentrated on microfabricated devices prior to separation and laser-induced fluorescence detection on the same device. The proteins were concentrated using a porous silica membrane between adjacent microchannels that allowed the passage of buffer ions but excluded larger migrating molecules. Concentrated analytes were then injected into the separation column for analysis.

Detection of exercise-induced ischemia by changes in B-type natriuretic peptides.

Objectives: The purpose of this study was to examine the effect of exercise-induced ischemia on levels of B-type natriuretic peptide (BNP) and its inactive N-terminal fragment (NT-pro-BNP)and to determine whether measurement of these peptides can improve the diagnostic accuracy of exercise testing.

Background: The ability of exercise testing to detect coronary artery disease (CAD) is limited by modest sensitivity and specificity. B-type natriuretic peptides (NT-pro-BNP and BNP) are released by ventricular myocytes in response to wall stress.