In-vacuum Faraday isolation remote tuning.

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.

In-vacuum optical isolation changes by heating in a Faraday isolator.

We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient convection cooling of the magneto-optic crystal of the Faraday isolator. An isolation decrease by a factor of 10 is experimentally observed in a Faraday isolator that is used in a gravitational wave experiment (Virgo) with a 10 W input laser when going from air to vacuum. A finite element model simulation reproduces with a great accuracy the experimental data measured on Virgo and on a test bench. A first set of measurements of the thermal lensing has been used to characterize the losses of the crystal, which depend on the sample. The isolation factor measured on Virgo confirms the simulation model and the absorption losses of 0.0016 +/- 0.0002/cm for the TGG magneto-optic crystal used in the Faraday isolator.

Efficacy and safety of micronised fenofibrate in a randomised double-blind study comparing four doses from 200 mg to 400 mg daily with placebo in patients with hypercholesterolemia.

The aim of this study was to evaluate the efficacy on LDL-cholesterol (LDL-C) of micronised fenofibrate given for three months at doses ranging from 200 to 400 mg once daily, compared with placebo. A double-blind, randomised, parallel-group, multi-centre trial was performed in four centers of France in 340 hypercholesterolemic patients (163M, 177F) aged 18-75 years. After a 2-3 month single-blind run-in period on placebo and diet, patients with LDL-C greater than or equal to 4.65 mmol/l (180 mg/dl) maintained on the same diet throughout the study were randomly allocated to placebo or to 200, 267, 340 or 400 mg micronised fenofibrate, given once daily with the evening meal for 3 months. LDL-C, total cholesterol (TC), total triglycerides (TG) and apolipoprotein B (Apo B) significantly decreased compared with placebo in all four fenofibrate groups. For all randomised patients, the decrease in the fenofibrate groups ranged from 31.6-38.8% for LDL-C, 24.5-31.9% for TC, 26.7-40.8% for TG, and 27.3-35.0% for Apo B. An increase in HDL-cholesterol of 4.1-8.2% was observed in the fenofibrate groups, but did not reach statistical significance. Lipid values in the placebo group remained unchanged. The therapeutic goal of LDL-C<3.36 mmol/l (130 mg/dl) was reached in 27% in the 200 mg group and increased to 56% in the 300 mg group. There were no major clinical or biological adverse events in the dose interval from 200 mg to 400 mg of micronised fenofibrate per day. This study showed treatment for 3 months with micronised fenofibrate at doses up to 400 mg per day is effective and can reduce LDL-cholesterol up to 30% allowing further evaluation of these doses on longer trials.

Cyclosporine determinations in heart and liver transplant recipients: comparison of HPLC and FPIA methods on whole blood and plasma.

One hundred and eighty five whole blood samples were analysed for cyclosporine levels by fluorescence polarization immunoassay (FPIA) and high performance liquid chromatography (HPLC). 123 came from 4 heart transplant recipients (mean age +/- SD: 47.50 +/- 20.56 years) and 62 from 4 liver transplant recipients (44.50 +/- 16.52 years). FPIA was done on plasma and whole blood in heart transplant recipients, on plasma in the liver recipients. HPLC was always done on whole blood. The results show a good correlation between FPIA on plasma (y) and HPLC (x) in liver recipients (n = 62, r = 0.935, y = 1.23x + 70 ng/ml), slightly worse between FPIA on plasma (y) and HPLC (x) in heart recipients (n = 64, r = 0.610, y = 0.78x + 189 ng/ml) and mediocre for FPIA on whole blood (y) and HPLC (x) in heart recipients (n = 123, r = 0.566, y = 1.35x + 594 ng/ml).

[Physiopathologic and clinical implications of protein C deficiencies]. / Implications physiopathologiques et cliniques des déficits en protéine C.

The protein C system--a complex physiological coagulation inhibition system--is a major regulator which controls thrombin production. Nowadays, its exploration is indispensable for the detection of constitutional or acquired protein C deficiency, side by side with a search for antithrombin III deficiency. This approach, based on the frequent association of recurrent thrombosis, mainly venous, in young subjects with congenital deficiencies, makes it possible to initiate, beside a family survey, an individual and efficient prophylaxis of recurrent thrombosis.

Potential usefulness of quinine to circumvent the anthracycline resistance in clinical practice.

Quinine, the widely used antimalaria agent, was found to increase the cytotoxicity of epideoxorubicin (epiDXR) in resistant DHD/K12 rat colon cancer cells in vitro. Quinine appeared as slightly less effective than quinidine or verapamil for anthracycline potentiation but its weaker cardiotoxicity could counterbalance this disadvantage in vivo. Serum from six patients treated by conventional doses of quinine (25-30 mg kg-1 day-1) was demonstrated to enhance the accumulation of epiDXR in DHD/K12 cells as judged by fluorescence microscopy and HPLC assay (1.6 to 6-fold compared with control serum). In this patients quinine concentrations in serum ranged from 4.4 to 10.1 micrograms ml-1. Our results suggest that quinine could be safely used as anthracycline resistance modifier in clinical practice.