The localisation of intracellular immunoglobulin and alpha-1-antitrypsin by immunoelectron staining of post-osmicated, resin-embedded tissue

Early lesions of proliferative enteritis in pigs and hamsters

Gnotobiotic pigs and conventional hamsters were given suspensions of intestinal mucosa from a pig with proliferative hemorrhagic enteropathy and killed 10 or 21 days later. Affected animals had evidence of marked proliferation of immature enterocytes in the intestinal crypts. Numerous Campylobacter-like organisms were in the cytoplasm of enterocytes, and in some instances, bacteria were closely associated with enterocytes. Some intracellular bacteria lying below the microvillous border were within membrane-bound structures. Immunofluorescence and electron immunogold staining with specific antibodies indicated that these organisms were antigenically different from curved bacteria in the crypt lumen of early lesions. This study indicates that the life cycle of the intracellular organisms may involve entry into crypt enterocytes from the intestinal lumen with subsequent intracellular multiplication.

Comparative study of two immunocytochemical techniques in the electron microscopical detection of alpha-1-antitrypsin in routinely processed liver biopsies

Two indirect immunocytochemical techniques using different markers, namely peroxidase and gold, were applied to ultrathin sections of liver biopsies to detect alpha-1-antitrypsin. The blocks used were taken from the routine electron microscopy files and had been processed optimally for maximum ultrastructural preservation. The immunogold technique provided the best method for localizing alpha-1-antitrypsin and was associated with ultrastructural preservation equivalent to that seen in routinely processed liver biopsies. The procedure may be a useful adjunct to understanding the pathogenesis of alpha-1-antitrypsin deficiency and in recognizing further variants of this disorder.

Immunogold localization of peroxisomal enzymes in Epon-embedded liver tissue. Enhancement of sensitivity by etching with ethanolic sodium hydroxide

Epon-embedded biological materials exhibit well preserved ultrastructure but generally weak antigenicity. Brief etching of ultrathin Epon sections with resin solvent, ethanolic sodium hydroxide, brought about a nearly 2-fold increase in the immunogold labeling density of rat and human hepatic peroxisomes after incubation with antisera against catalase and 3 enzymes of lipid beta-oxidation: acyl-CoA oxidase, bifunctional protein (enoyl-CoA hydratase-3-hydroxyacyl-CoA dehydrogenase) and 3-ketoacyl-CoA thiolase. The etching was superior to pretreatment with an oxidant, sodium metaperiodate. Despite some deterioration of the cellular ultrastructure, the obtained enhancement of the sensitivity of the protein A-gold method may be helpful in cases when the antigenicity to be detected is strongly inhibited by epoxy resin embedding.