Abstract: Systems and methods are described providing a hepatic recycling glucose tolerance test for the diagnosis of types and subtypes of diabetes mellitus and other hyperglycemic or hypoglycemic conditions. A method is also provided for screening candidate drugs for treating various types of abnormal glucose metabolism and to monitor whether the course of treatment is effective. The method also allows the correlation of gene activity, hormone and metabolite levels with glucose flux and recycling and an assessment of the degree of hepatic insulin resistance. The method utilizes a preferably non-radioactive stable labeled glucose to asses the relative rates of carbon flow in the liver and provides a hepatic recycling constant that is a measure of the relative rate of glucose recycling. The labeled glucose may be introduced to the patient orally, intravenously or by intraperitoneal administration for the desired effect.

Abstract: A film spool of the type which is rotatable inside a light-tight cassette shell as a film strip coiled about the spool is pulled out of the shell, has a film exposure status indicator movable from a first position to a second position where it provides a visible indication that the film is completely exposed. The status indicator includes an element movable within the hollow interior of the spool core between the first and second positions, a spring urging the element towards the second position, and a retaining device cooperating with an end portion of the film strip to prevent movement of the element until the film strip has been fully unwound.