UNLABELLED Tumor cells lacking the functional p53 suppressor gene may arrest at the G2 phase of the cell cycle after exposure to ionizing radiation, resulting in increased radioresistance. Methylxanthines (MTXs), such as pentoxifylline (PTX) or caffeine (CAF), can inhibit the G2-phase checkpoint arrest of damaged cells and thus radiosensitize them. However, the effect of MTX in cells irradiated...

OBJECTIVES The purpose of this study was to compare the voltage-dependent K(+) currents of human cells of the right and left atria and determine whether electrical remodeling produced by chronic atrial fibrillation (CAF) is chamber-specific. BACKGROUND Several data point to the existence of interatrial differences in the repolarizing currents. Therefore, it could be possible that CAF-induced ...

This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg(-1)·min(-1)) performed a graded ...

The complex antenna factor (CAF) introduced to measure transient electromagnetic fields or electromagnetic pulses and its applications are investigated. The equations of the three-antenna method for determining the CAF of a dipole antenna, a log-periodic dipole array antenna (LPDA), and a monopole antenna are derived. The results of the waveform reconstructions using the CAF are compared with t...

During the last years an increased interest has been observed on tools analyzing collaborative interactions that could be useful for researchers, teachers, or even students. The paper presents such a tool, based on the formally defined Collaborative Activity Function (CAF). The empirical evaluation of CAF is also presented. The evaluation is focused on teachers using CAF during and after sessio...

CD8(+) T lymphocytes can suppress human immunodeficiency virus type 1 (HIV-1) replication by secreting a soluble factor(s) known as CD8(+) T-lymphocyte antiviral factor (CAF). One site of CAF action is inhibition of HIV-1 RNA transcription, particularly at the step of long terminal repeat (LTR)-driven gene expression. However, the mechanism by which CAF inhibits LTR activation is not understood...