The use, in diabetic rats and monkeys, of artificial capillary units containing cultured islets of Langerhans (artificial endocrine pancreas).

A unit was constructed that consisted of a core of hollow fibers through which low-molecular-weight substances, such as glucose and insulin, could pass freely but were impermeable to high-molecular-weight proteins, such as antibodies. Islets of Langerhans from normal rats were planted in the space surrounding the fibers, and either blood or nutrient medium was circulated through the fibers themselves. In experiments with animals, the units were attached to the vascular system of diabetic rats and monkeys.

The use of foetal, calf and adult bovine sera for the growth of serially subcultivated diploid cells.

Medium CMRL-1969 supplemented with either foetal calf, calf or adult bovine sera, or a combination of the various sera, was used to subcultivate diploid cells for the preparation of substrates for vaccine production. Supplementation with calf or adult bovine sera gave satisfactory cell yields for at least 3-4 population doublings. The finite lifespan of the diploid cells grown in media supplemented with foetal calf was always longer than with calf or adult bovine sera.

Large-scale cultivation of cells in closed systems: stationary and moving.

Basic metabolic differences have been observed for cell cultures propagated in conventional stationary or rotating systems. The influence of these differences on virus characteristics is largely unknown but could be significant in maintenance of genetic stability of attenuated strains. Current requirements for good manufacturing procedures prompted the development of closed systems for both stationary and rotating cultures.

Karyology: vaccine manufacturers' views.

Chromosomal analyses and life span studies of WI-38 cell cultures used for vaccine production at the Connaught Laboratories Ltd will be described. Twenty cultures derived from the same seed lot and 25 cultures derived from different starter cultures were analyzed. Karyology tests at population doublings 31 and higher were within acceptable limits.