Frederick Banting realized that this procedure would destroy the trypsin-secreting cells but not the insulin. Once the trypsin-secreting cells had died, insulin could be extracted from the islets of Langerhans. Banting discussed this approach with J. J. R. Macleod, Professor of Physiology at the University of Toronto. Macleod provided experimental facilities and the assistance of one of his students, Charles Best. Banting and Best, with the assistance of biochemist James Collip, began the production of insulin by this means. As the experiments proceeded, the required quantities could no longer be obtained by performing surgery on living dogs. In November 1921, Banting hit
Highest and best use a series of tests. The exact definition of highest and best use varies, but generally the use must be the following: Only those uses that are, or may be, legally permitted are potential highest and best uses. This may exclude uses that are not, and unlikely to become, permitted by zoning, land use planning, uses forbidden by government regulations, and uses prohibited by deed restrictions or covenants. Properties with a use that predates existing zoning or other property regulations may be "legally nonconforming". Such "grandfathered uses" are generally legal even though they do not meet current zoning or other regulations.