Biomedical subjects

S Batsford

Publications and source records attributed to S Batsford.

40 records · Page 3Linked to original sources

PubMed1980

An approach to postembedding staining of protein (immunoglobulin) antigen embedded in plastic: prerequisites and limitations.

A method is described for performing postembedding staining of protein (immunoglobulin) antigen embedded in styrene-methacrylate resin. Fixation of specimens in a combination of 4% paraformaldehyde and 0.2% picric acid and washing in buffer containing 7% sucrose, followed by abrupt dehydration with absolute acetone in the cold preserved the antigenicity, although in a masked form. The masked antigenicity could be reexposed by treatment with nonspecific protease. Staining with fluorescent-, peroxidase-, or ferritin-labeled antibodies on semi- and ultrathin sections resulted in specific localization of the antigen. We applied this technique to the localization of rabbit immunoglobulin in specimens of renal tissue obtained from rats with anti-glomerular basement membrane nephritis; we also localized human IgG in a renal biopsy specimen. The prerequisites for recovery of antigenicity are such that preservation of tissue structure at the light microscopic level is good, but relatively poor at the electron microscopic level.

Animals↗

PubMed1980

'In situ' immune complex nephritis and basic proteins.

This investigation was designed to clarify the potential role of basic antigens in immune complex nephritis. The GBM is negatively charged and binds cationic substances. We studied 1) whether chemically cationised proteins can bind to the GBM, act as planted antigen, and induce 'in situ' immune complex formation or 2) if a pre-formed cationic antigen antibody complex can localise in the GBM. Results obtained with 5 chemically cationised proteins support the first possibility.

Animals↗

PubMed1979

Immuno-electron microscopic localization of lipopolysaccharide antigens on ultrathin sections of Salmonella typhimurium.

Lipopolysaccharide antigens were demonstrated on ultrathin sections of styrene-embedded Salmonella typhimurium by direct postembedding staining with ferritin-labeled antibodies. The antigenicity, partially masked in the embedding process, could be satisfactorily recovered by treatment of ultrathin sections with nonspecific protease. As judged from the reaction site of the ferritin-labeled antibodies, the lipopolysaccharides were localized in two zones. The broader zone of densely distributed ferritin molecules was superimposed over the whole outer cellwall, and a smaller zone revealing antigenicity was found over the cell membrane, which strongly supports the concept that the latter is the site of synthesis of lipopolysaccharides. The well-defined labeled areas between these two antigenic zones may be the routes whereby the synthesized polysaccharide molecules reach the cell wall.

Antigen-Antibody Reactions↗

PubMed1979

Comparison of the handling of ferritin and ferritin-protein conjugates by the glomerular mesangium: kinetic studies in the rat.

Kinetic studies on the uptake and elimination of ferritin and ferritin-protein conjugates in the rat glomerular mesangium are reported. Ferritin was prepared from horse spleens and conjugates were prepared using either human IgG or albumin. The degree of mesangial uptake was dose dependent and a competitive effect with the reticuloendothelial system was observed. Maximal mesangial fluorescence occurred at a lower dosage with conjugate than with native ferritin. In addition, conjugate persisted for months within the mesangium as compared to a matter of days in the case of ferritin alone. The disappearance of native ferritin from the mesangium paralleled that seen in the circulation. Conjugate, however, disappeared far more rapidly from the circulation than from the mesangium. At a point in time when the mesangium still contained conjugate but the blood was negative, rabbit antiserum to ferritin was injected and was observed to deposit in the mesangium. This demonstrated the accessibility of mesangially sequestered antigen to circulating antibody. This system provides a model for long term studies on the effect of immune reactions occurring in the mesangium.

Animals↗