The mechanism accounted for the silver staining "fast techniques" development and its histochemical meaning. II. The binding between silver and ferric ion accounted for the silver staining development.

Results obtained on filter paper strips models show that some protein and fatty acids become argentophil as an effect of a previously binding ferric ion although, in this instance, the silver staining can only be accomplished by using a silver diamine solution, since a silver nitrate solution is not effective. However, if the filter paper model is previously treated by a "multidentate ligand" before the silver nitrate solution treatment becomes able in doing the silver staining. This result shows that the binding between Fe3+ and Ag+ can be done if a suitable negatively charged "multidentate ligand" has been connected between them.

The mechanism accounted for the silver staining "fast technique" development and its histochemical meaning: I. The correlation between the silver staining intensity and the tissue bound ferric ion and some other tissue histochemical reactivities.

The mechanism accounted to accomplish the silver staining "fast technique" on tissues sections was studied towards the correlation among histophotometric measures concerning the silver staining intensity and the intensity provided by some histochemical reactions performed on spleen and liver sections from rats and pigs. By treating previously these histological sections with thioglycolate or oxalate solutions in progressive concentrations and afterwards subjecting them to a silver staining "fast technique", it was demonstrated that the silver staining intensity decreases proportionally to the thioglycolate or the oxalate solution concentration. The regression line of the silver staining intensity on the thioglycolate or the oxalate solution concentration was established, as well as its regression coefficient.

Quantitative assay of Schieff and PAS reactivity during nerve degeneration in rats.

Quantative histochemical analysis of nerve degeneration in rats from zero to 192 hours was studied utilizing both Schiff reagent and PAS reaction. In addition, amylase digestion prior to PAS staining and aniline blockade of Schiff reactivity were employed. The staining intensity of all the reaction was measured histophotometrically and the mean optical density (OD) was determined for the following time intervals: 0, 24, 48, 96, and 192 hours.

Histochemistry of the amyloid substance from familial amyloidotic polyneuropathy.

The histochemical properties of the amyloid substance from familial amyloidotic polyneuropathy (FAP) were studied. The results showed differences among the FAP amyloid and the others amyloid substance. The main difference being that FAP amyloid substance was free of or only contain a small amount of protein.