Extracorporeal irradiation of blood in goats with fully portable irradiators

A fully portable vitreous carbon-170Tm blood irradiator in a carotid-jugular shunt reduces lymphocyte levels in goats, with recovery to preirradiation levels requiring several months. It appears that lymphocyte response to chronic irradiation is more closely related to daily cumulative dose than to acute dose (transit dose) delivered to blood during a single pass through the irradiator. Testing of different dose regimens is proceeding along with design changes being made to facilitate ultimate clinical evaluation. Umits now being tested utilize pristine vitreous carbon as the blood interface and isotope containment material. Scanning electron microscopy shows that material to be extremely smooth and initial testing in arteriovenous shunts indicates it is nonthrombogenic. Results of animal experiments now in progress will be presented in terms of lymphocytopenia induction and changes in cellular immune response; this will be compared with data published by others using intermittemt acute exposures achieved with nonportable extracorporeal blood irradiator equipment