AIMS Biomarkers can be used for diagnosis, risk stratification, or management of patients with heart failure (HF). Knowledge about the biological variation is needed for proper interpretation of serial measurements. Therefore, we aimed to determine and compare the biological variation of a large panel of biomarkers in healthy subjects and in patients with chronic HF. METHODS AND RESULTS The b...

In concentration-QTc modeling, oscillatory functions have been used to characterize biological rhythms in QTc profiles. Fitting such functions is not always feasible because it requires sufficient electrocardiograph sampling. In this study, drug concentration and QTc data were simulated using a published biological QTc model (oscillatory functions). Then, linear mixed-effect models and the biol...

We used an automated recording system and computer analysis to perform hourly QRS subtractions on ECG signals obtained with dipolar leads in 14 patients admitted within 6 hours of the onset of symptoms of acute myocardial infarction (AMI). The resulting changes in QRS time-voltage area were expressed as a difference vector (QRSMD) which was found to have a simple time course that was similar fo...

Background: The affinity of an antibody to its antigen is a crucial parameter in its biological activity and performance of an immunoassay such as ELISA. Affinity of most IgG specific MAbs are often determined by methods which require labeling of either antigen or antibody, and are sometimes difficult to control, do not always lead to the expected signal and often result in immunological modifi...

background: although various surface disinfectants have been introduced, most of them are toxic. the use of natural antimicrobial agent e.g. phytol, extracted from leptadenia pyrotechnica is a new strategy. the aim of this study was to evaluate the antimicrobial activity, toxicity, and stability of phytol. methods: the serial concentrations of phytol were prepared, and separately incubated with...

To date, our understanding of how DNA is packaged in the cell nucleus, condensed from chromatin into chromosomes, and organized throughout cycle remains sparse. Three dimensional (3D) ultrastructural imaging an important tool for unravelling organizational structure chromosomes. For large volume 3D biological samples, serial block-face scanning electron microscopy (SBFSEM) has been applied, whe...