Ultraviolet (UV)-B irradiation abolishes lymphocyte functions (the ability to respond and to stimulate) in mixed lymphocyte culture (MLC). This effect may have practical application in the prevention or reduction of transfusion-induced alloimmunization against HLA class I antigens. To study this, platelet concentrates (PCs) were obtained with a cell separator, suspended in autologous plasma in a final volume of 400 mL, and transferred into a large (22 X 30 cm) cell culture bag. This plastic showed a good transmittance of UV-B rays at 310 nm (54%). PCs were placed between two quartz plates (surface of irradiation = 25 X 37 cm), and the two sides were irradiated simultaneously. Energy delivered to the surface of the plastic bag was automatically monitored. The ability to respond (in MLC and to phytohemagglutinin) and to stimulate allogeneic lymphocytes was completely abolished with energy of 0.75 J per cm2 (irradiation time less than 3 min). The temperature increase during irradiation was negligible. Platelet aggregation (collagen, adrenalin, ADP, arachidonic acid, ristocetin) was not impaired if UV-B energy was below 3 J per cm2. Recovery and survival of autologous 111In-labeled platelets were studied in four volunteers; no differences were found between UV-B-treated (1.5 J/cm2) platelets and untreated platelets. These results show that a large-scale clinical trial using UV-B-irradiated PCs to prevent HLA alloimmunization is feasible.
Les auteurs indiquent la source des données sur lesquelles, en 1986, l'autorité de santé a évalué le risque des retombées radioactives de l'accident de Tchernobyl en France. Ils décrivent les moyens mis en oeuvre pour acquérir ces données, l'expérience précédemment acquise, puis l'essentiel des résultats de mesures. Ils confirment les termes de la note du 28 mai 1986 de R. Latarjet à l'Académie des sciences, concluant que ces retombées ont été très inférieures à ce qui aurait pu justifier des contre-mesures autres que le contrôle des denrées importées. Ils estiment nécessaire de prendre des dispositions pour améliorer la communication impliquant, selon le modèle suédois, l'intervention du corps médical compétent en médecine nucléaire et en radiotoxicologie.
The following list shows the age measurements carried out from 1958 to March 1963 at the Radiocarbon Laboratory at Gif-sur-Yvette, This laboratory has been replaced by a new one whose first measurements are also given in this volume.It was equipped with 2 proportional counters similar to those used in Saclay laboratory and operating with 1 atm of pure CO2. These counters were shielded by 15 cm lead, 5 cm iron and 1.5 cm of mercury.Data have been calculated on the basis of a C14 half-life of 5570 yr, in agreement with the decision of the Fifth Radiocarbon Dating Conference. As a modern carbon standard, wood taken from old furniture was used. This standard was found equivalent to 95% of the activity of the NBS oxalic acid, if a 2% Suess-effect is adopted for this wood.
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