Effect of ethanol in Paclitaxel injections on the ethanol concentration in exhaled breath.

BACKGROUND: Ethanol is included in certain injectable preparations of anticancer drugs to increase their solubility. Since the volume of ethanol in these preparations is approximately half of the total injection volume, the potential inhibitory effects of ethanol on the central nervous system cannot be disregarded, especially considering that patients may drive immediately after administration of the medication. Therefore, the concentration of ethanol was examined in exhaled breath after administration of paclitaxel, an anticancer medication containing ethanol. METHODS: The ethanol concentration in exhaled breath immediately after an intravenous infusion of paclitaxel was measured in 30 patients, using a balloon-type gas detector tube. Correlations between the concentration of ethanol in exhaled breath and the total amount of ethanol administered or the intravenous infusion speed were calculated. RESULTS: The mean ethanol concentration in exhaled breath was 0.028 ± 0.015 mg/L. The correlation between the ethanol concentration in exhaled breath and the total dose of ethanol was weak (R2 = 0.25; p = 0.055), while the intravenous infusion speed showed a stronger positive correlation with the concentration of ethanol in the breath (R2 = 0.49; p = 0.11). The maximum concentration of ethanol measured in exhaled breath (0.06 mg/L) was equivalent to 40% of the threshold for drunk driving, as specified in the Road Traffic Act in Japan. CONCLUSION: In this study, no patient had a breath ethanol concentration exceeding the legal threshold for drunk driving. However, it is still advisable for patients to avoid driving after receiving paclitaxel injections. When driving cannot be avoided, patients should wait for a sufficient time after receiving the injection before driving.

Irregular lasing pattern formation and dynamic effects in a thin-slice solid-state laser.

We found an abrupt transverse-mode transition from an irregular to a Gaussian lasing pattern or billiard-like lasing patterns with increasing the pump power in a laser-diode-pumped thin-slice Nd:GdVO4 laser with coated dielectric mirrors on both ends. A variety of irregular stationary lasing patterns were observed with a slight change in the pump position due to polished crystal surface roughness and ineffective lasing field confinement in transverse directions. A physical interpretation for observed irregular patterns was given in terms of wave formations in gradient refractive index lens with undulated reflective end surfaces. Intensity modulation of the laser, resulting from the interference of non-orthogonal transverse mode pairs embedded in the irregular lasing patterns, and associated rich chaotic pulsations were demonstrated. Observed nonlinear dynamics were well reproduced by numerical simulation.

Modal interference and dynamical instability in a solid-state slice laser with asymmetric end-pumping.

We observed complicated emission patterns consisting of different transverse modes and associated intensity pulsations at beat frequencies between pairs of transverse eigenmodes in a solid-state thin-slice Fabry-Perot laser with asymmetric end-pumping. The dependence of transverse patterns and pulsation frequencies on pump power has been demonstrated. The interference among nonorthogonal transverse eigenmodes, which are formed in a deformed Fabry-Perot microcavity possessing an asymmetric, gradient refractive-index potential for optical waves, is proposed for explaining observed instabilities. Intensity modulations have been remarkably reproduced by numerical simulations of model equations.

Self-induced high-speed modulation in microchip solid-state lasers with asymmetric end pumping.

We applied laser-diode sheetlike end pumping to a multimode Nd:YVO(4) laser and observed high-speed (>400-MHz) modulation of the intensity of chaotic pulsation near 1 MHz. The frequencies of modulation were the beat frequencies for pairs of closely spaced lasing modes. Asymmetric optical confinement and the resultant modal interference are shown to lead to oval-hollow-mode operation in which modal beat notes induce high-speed modulation, the frequency range of which is 2 orders of magnitude higher than the intrinsic relaxation oscillation frequency. Good numerical reproduction of the observed chaotic pulsations and their high-speed modulation was obtained with model equations in which such effects as nonlinear gain coupling among modes and field interference between pairs of modes were included. High-speed pulsations in nonchaotic lasers were also demonstrated.