Determination of a new oral iron chelator, ICL670, and its iron complex in plasma by high-performance liquid chromatography and ultraviolet detection.

ICL670 is a representative of a new class of orally active tridentate selective iron chelators. Two molecules of ICL670 are required to form a complete hexacoordinate chelate Fe-[ICL670]2 with one ferric iron. A simple and rapid HPLC-UV method for the separate determination of ICL670 and Fe-[ICL670]2 in the plasma of iron-overloaded patients is described. Plasma samples were prepared as rapidly as possible, the tubes being kept at 4 degrees C. Plasma proteins were precipitated with methanol. The supernatant was diluted with water and placed on the refrigerated sample rack of an autosampler before injection. The chromatographic separations were achieved on an Alltima C18 column using 0.05 M Na2HPO4 and 0.01 M tetrabutylammonium hydrogen sulfate-acetonitrile-methanol (41:9:50, v/v/v) as mobile phase. The analytes were detected at 295 nm. Calibration and quality control samples were prepared in normal human plasma. The mean accuracy (n=6) over the entire investigated concentration range 0.25-20 microg/ml ranged from 91 to 109% with a coefficient of variation (C.V.) from 4 to 8% for ICL670, and from 95 to 105% with a C.V. from 2 to 20% for the iron complex. The dissociation of the complex during analysis was shown to be marginal. The iron removal from plasma of iron-overloaded patients by free ICL670 during analysis was low. The in vitro iron transfer from the iron pools of iron-overloaded plasma onto ICL670 was shown to be a slow process

Wavefront sensing in propagation and imaging though the atmosphere

Tire de SPIE's technical symposium on optical engineering and photonics in aerospace sensing, Orlando, April 16-20, 1990SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1990 n.98 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

High resolution imaging through atmospheric turbulence : link between anisoplanetism and intensity fluctuations

Communication to : SPIE conference on optics in atmospheric propagation and adaptive systems III, Florence (Italy), September 21-24, 1999SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2000 n.205 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

[Multicenter study on the litholytic effect of ursodeoxycholic acid. 30 cases].

In the context of a cooperative clinical trial carried out in the Cantons of Basel and Vaud, Switzerland, the litholytic effect of ursodeoxycholic acid (Ursochol) in a daily dose of 9 mg/kg was investigated in 42 patients with radiotransparent gallstones. The litholytic effect was evident in 22 (73%) of the 30 patients followed up for a maximum period of 1 year. Complete dissolution of gallstones was obtained in 40% of cases. In addition, ursodeoxycholic acid significantly reduced (p less than 0,001) the dyspeptic-painful symptoms and the number of biliary colics. Tolerance was excellent. In particular, no cases of diarrhea were observed

Wavefront sensing in imaging through the atmosphere A detector strategy

Tire de : proceedings of 'SPIE's 36th annual symp. on optical and optoelectronic applied science and engineering', San Diego, CA (USA), July 21-26, 1991SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1991 n.165 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

The effect of zolpidem on cognitive function and postural control at high altitude

Study Objectives Sleep is altered at high altitude leading many mountaineers to use hypnotics in order to improve sleep efficiency. While after a full night at altitude the short-acting hypnotic zolpidem does not appear to alter cognitive function, residual adverse effects should be considered following early waking-up as performed by mountaineers. We hypothesized that zolpidem intake at high altitude would alter cognitive function 4 hours after drug intake. Methods In a randomized double-blind controlled cross-over study, 22 participants were evaluated during two nights at sea level and two nights at 3800 m, 4 hours after zolpidem (10 mg) or placebo intake at 10:00 pm. Polygraphic recording was performed until waking-up at 01:30 am. Sleep quality, sleepiness and symptoms of acute mountain sickness were assessed by questionnaires. Two cognitive tasks (Simon task and duration-production task) were performed at rest and during exercise and postural control was evaluated. Results Zolpidem increased reaction time in all conditions (zolpidem 407 ± 9 ms vs. placebo 380 ± 11 ms; p < 0.001) and error rate in incongruent trials only (10.2 ± 1.1% vs. 7.8 ± 0.8%; p < 0.01) in the Simon task and increased time perception variability (p < 0.001). Zolpidem also altered postural parameters (e.g. center of pressure area, zolpidem 236 ± 171.5 mm 2 vs. placebo 119.6 ± 59 mm 2; p < 0.001). Zolpidem did not affect apnea-hypopnea index and mean arterial oxygen saturation (p > 0.05) but increased sleep quality (p < 0.001). Zolpidem increased symptoms of acute mountain sickness and sleepiness (p < 0.05). Conclusions Acute zolpidem intake at high altitude alters cognitive functions and postural control during early wakening which may be deleterious for safety and performances of climbers