Changes
in drug-metabolizing activity via pregnane X receptor (PXR) is one of the
mechanisms involved in drug-drug interactions. The authors reported cases in
which the anticoagulant effects of warfarin were reversibly attenuated by the
concomitant administration of rifampicin or bosentan, which are potent PXR
ligands. However, no recovery of the response to warfarin was observed in the
patients switched from bosentan to macitentan, which is considered not to
activate PXR in clinical settings. The authors describe the importance of
long-term monitoring and additional examinations to clarify the sustained mechanism
for the drug interaction with warfarin, when switching from bosentan to
macitentan.
The dust extinction coefficient measured by
light detection and ranging (LIDAR) has been used as an indicator of exposure
to Asian dust in many epidemiological studies; however, few reports exist which
explore the relationship between the dust extinction coefficient and the
distribution of airborne particles near the ground surface. In this study,
authors repot that the dust extinction coefficient is a useful indicator of
Asian dust near the ground surface; however, as harmful air pollutants
occasionally move with Asian dust, it is necessary to monitor these pollutants
near the ground surface when conducting an epidemiological study on the health
effect of airborne particles.
Circadian
rhythms influence various physiological functions, including drug distribution
and efficacy. However, the influence of circadian
rhythms on the blood-brain barrier (BBB) remains unclear. Ogata et
al. comprehensively investigated diurnal protein changes in
mouse BBB by quantitative proteomics analysis. Expression
of proteins associated with transport and physical barrier at the BBB remained constant
throughout the day, whereas expression of proteins involved in protein
synthesis, angiogenesis, and energy metabolism varied diurnally. These findings
may help predict
the biological responses to circadian changes in the BBB and brain drug
distribution.
An
administration plan for vancomycin in bedridden elderly patients has not been
established. This study evaluated the prediction accuracy of the
Bayesian-derived area under the concentration-time curve (AUC) of vancomycin
using creatinine-based equations for estimating kidney function in such
patients. In this paper, the authors showed that the Bayesian approach using the
estimated creatinine clearance calculated by substituting the serum creatinine
level + 0.2 into the Cockcroft-Gault equation has the highest prediction
accuracy for the AUC in bedridden elderly patients. These results may
contribute to improving the efficacy and safety of vancomycin in such patients.
Recently, chemotherapy-induced
secondary sarcopenia has emerged as an important clinical issue; however, the
underlying mechanisms are poorly understood. In this study, the authors focused
on the possible involvement of mitochondrial disturbances in cisplatin-induced
muscle atrophy using a cellular model. They concluded that mitochondrial
dysfunction and the resultant generation of excessive reactive oxygen species
(ROS), but not energy disruption, play a central role in cisplatin-induced
C2C12 myotube atrophy. These results suggest that mitochondrial protection
and/or ROS scavenging may be promising strategies for preventing muscle atrophy
associated with cisplatin-based chemotherapy.