Abstract: The method of treating Alzheimer's disease which comprises administering to a patient having the disease a safe and effective amount of a biologically active vitamin D.sub.3 or D.sub.2 material.

Abstract: A method is described for preparing tissue samples for use in diagnostic evaluation involving the rapid fixation, dehydration, and embedding of a tissue sample as well as rapid mounting of plastic sections to glass slides, dissolution of plastic and optimal staining of tissure components. The rapid and controllable fixation and the dehydration of the tissue sample utilizes the denaturing effects of microwaves on the proteins in combination with a heat sink. Alternatively, the dehydration of the tissue sample utilizes the principles of freeze drying. The tissue sample can be embedded using conventional paraffin embedding or plastic embedding techniques. Rapid penetration of plastic into the tissue is facilitated by microwaves, adhesion of plastic sections to glass slides is promoted by microwaves, as is the fast and optimal staining of tissue components. The method of this invention provides a very rapid technique for processing of tissue for diagnostic and analytic evaluation.