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Biomedical subjects

H Takamiya

Publications and source records attributed to H Takamiya.

At least 55 records · Page 3Linked to original sources
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

Immunohistological staining of antigens on semithin sections of specimens embedded in plastic (GMA-Quetol 523).

Glycol methacrylate-Quetol 523, introduced by Kushida (1977) for combined light and electronmicroscopy studies at low magnification, also permits application of immunofluorescence methods to semithin sections. To recover the antigenicity of proteins fixed with formaldehyde, abrupt dehydration before embedding and subsequent treatment of the semithin sections with protease were essential. Post-staining with suitable histological stains allows exact correlation of antigen localization with tissue structure.

Acrylic Resins↗
PubMed1979

The isolation of an optimal small size immunoferritin conjugate fraction.

A procedure is described for preparing immunoferritin conjugates consisting of one antibody molecule attached to one ferritin molecule. Results obtained with such a reagent faithfully reflect the true distribution of antigenic determinants, and allow more accurate quantification.

Antibodies, Fungal↗
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

Autoantibody specific for the glomerular mesangium and Bowman's capsule in man.

Investigation of serum from a nominally healthy subject revealed an unusual autoantibody with specificity for the glomerular mesangium and Bowman's capsule. Immunofluorescence studies on rodent kidney sections revealed typical mesangial fluorescence and intense linear staining of Bowman's capsule. The antibody was organ, but not species, specific and did not correspond to any previously described antibody with anti-mesangial activity (e.g. anti-actomyosin or anti-fibronectin). Intravenous injection in mice resulted in heavy mesangial deposition of antibody within one hour, the antibody disappeared within 2--4 weeks, and no urinary abnormalities were seen. Retrospective analysis of clinical data revealed a history of chronic hepatitis and possible drug abuse, but no evidence for impaired renal function at any timepoint. To our knowledge this is the first report of specific anti-mesangial antibody in man, the pathogenetic relevance remains unclear.

Animals↗
PubMed1979

Pathogenetic role of mesangial immune deposits.

This investigation was designed to clarify the pathogenetic role of immune complexes within the mesangium. We administered a ferritin-protein antigen to rats which localised and persisted within the mesangium. Subsequently administration of anti-ferritin antibody resulted in binding of antibody to the mesangially located antigen. The effect of this immune complex formed in situ was studied in long-term experiments and no evidence of glomerular impairment was seen. These results lend support to the view that an immunological process, confined to the mesangium, may not necessarily compromise renal function.

Animals↗
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↗
PubMed1978

Separation of anti-dinitrophenyl antibodies according to affinity by fractionated elution from immunoadsorbent using thiocyanate.

The possibility of fractionating anti-DNP-antibodies according to their affinity by successive elution from a DNP-immunoadsorbent with increasing concentrations of thiocyanate (KSCN) was investigated. Using KSCN at molarities of 0.5 M, 2.0 M and 3.0 M in a stepwise elution procedure, the mean affinity of the eluted antibody fractions was found to increase with increasing molarity of the eluent. The method described is a simple, reliable means of separating antibodies on an affinity basis which is of special value in systems where haptens are not available.

Animals↗
PubMed1978

Masking of protein antigen by modification of amino groups with carbobenzoxychloride (benzyl chloroformate) and demasking by treatment with nonspecific protease.

Cryostat sections of various substrates were treated with carbobenzoxychloride in acetone to modify antigens. By applying specific fluorescent antibodies, it could be shown that the antigenic determinants of rabbit gamma-globulin and bovine insulin were totally masked. The antigenicity of ACTH was markedly reduced, whereas the polysaccharide antigens of Salmonella typhimurium were only partially masked. After masking, antigenicity could be restored by treatment with nonspecific protease. The reversible protection of amino groups by carbobenzoxychloride may be a way to preserve protein antigens during embedding in plastics, as such materials also bind to amino groups, blocking the antigenicity of proteins.

Acetone↗
PubMed1978

Effect of antibody avidity on the induction of renal injury in anti-glomerular basement membrane nephritis.

Antibodies to glomerular basement membrane (GBM) of the rat could be fractionated according to their avidity by elution from trypsin-digested GBM (bound to Sepharose) with increasing concentrations of KSCN. The percentage of kidney-fixing antibody in each fraction and the degree of proteinuria induced as determined 24 h after injection increased with the avidity of the antibody fraction when equal doses were administered.

Animals↗
PubMed1977

[Electron microscopic presentation of immune reactions on Candida cells: asteroid bodies in Candida albicans from the urine of nephritis patients].

Candida albicans cells from the urine of two nephritis patients were concentrated and incubated with ferritin-labeled antihuman grammaglobulin (either anti-IgA, anti-IgG, or anti-IgM). Electron microscopy showed the electron-transparent yeast cell wall to be surrounded by an electron-dense capsule-like substance of remarkable volume. This must be regarded as an antigen-antibody precipitate corresponding to the "asteroid body" of previous authors. The antibodies involved in the formation of the precipitate are mainly those of the IgA and IgG classes. Considering the results of previous authors, the following definition is proposed: "Asteroid Bodies" are light microscopically visible antigen-antibody precipitates on the cell wall of fungi parasitic condition.

Antigen-Antibody Reactions↗
PubMed1975

A two-stage method for cross-linking antibody globulin to ferritin by glutaraldehyde. III. Size and antibody activity of the conjugates.

Immunoferritin conjugates consist of conjugates of different size. They can be separated in 4.5% polyacrylamide gel electrophoresis into at least 4 bands. The amount of the smallest 1:1 conjugate, in which one antibody molecule is linked to one ferritin molecule, is highest in coupling products with low overall yields of conjugated ferritin. Therefore relatively mild reaction conditions are recommended. With increasing size the antibody binding capacity of the conjugate is reduced.

Animals↗