[The "important physician"].
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Attitude of Health Personnel↗
Biomedical subjects
C Wittenbrink
Publications and source records attributed to C Wittenbrink.
Liver membrane antibodies (LMA) recognize a 26-kD protein on the hepatocellular surface.
Sera from 82 patients with chronic inflammatory liver diseases and from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Hashimoto's thyroiditis were studied by immunoblotting against purified liver plasma membranes (LPM) and soluble liver protein (SLP) fractions from different species after previous separation by SDS-PAGE. Eighteen of 19 sera with LMA of IgG type in immunofluorescence assay and six LMA-negative sera (three sera from patients with RA) showed antibodies of the IgG or IgM classes against a protein with a molecular weight of 26 kD which was present in LPM and SLP fractions from rats, rabbits, pigs and humans. The reaction with 26-kD liver protein did not correlate with other known autoantibody-antigen systems. All sera were negative in the 26-kD region with liver mitochondria, liver microsomes and soluble proteins of kidney (with one exception), heart and gut from the rat. The 26-kD protein was purified by affinity chromatography on immobilized anti-26-kD protein antibodies from patients, eluted from the 26-kD band of immunoblots. Studies with purified 26-kD liver protein and with SLP as antigens after separation in two-dimensional electrophoresis confirmed that patient serum and experimental rabbit antiserum react with the same protein. Eluted patient antibodies and rabbit antisera showed a linear fluorescence pattern on isolated hepatocytes from rat and rabbit. The data indicate that one of the target antigens of LMA is a species-nonspecific 26-kD protein located on the hepatocellular surface.
Adolescent↗
Glycoproteins of rat liver plasma membranes: their hepatocellular, intestinal and renal expression in rat, rabbit and human.
Expression of six glycoproteins (Mr = 60,000 (gp 60), 80,000 (gp 80), 110,000 (gp 110), 120,000 (gp 120), 140,000 (gp 140), 160,000 (gp 160)) recently purified from rat liver plasma membranes (LPM) were compared in the liver, small intestine and kidney of the rat, rabbit and human. Immunoblotting studies with monospecific antisera showed that five of the six glycoproteins (gp 60, gp 80, gp 110, gp 120, and gp 140) were expressed not only in LPM of the rat but also in LPM from the rabbit and human with Mr corresponding to those of the glycoproteins isolated from the rat. In contrast, the glycoprotein gp 160 was only detected in rat liver. The same pattern of expression was found by immunofluorescence on isolated hepatocytes from the three species. In rat liver, the glycoproteins were localized primarily either in the bile canalicular domain (gp 80, gp 110, gp 120), or in the sinusoidal domain (gp 60, gp 140), or they were distributed over the whole hepatocellular surface (gp 160). In rat, but not in rabbit or human, the glycoproteins gp 110, gp 120 and gp 140 were also found in the small intestine localized either in the brush border membrane (gp 110, gp 120) or over the whole surface membrane of enterocytes (gp 140). Gp 120 was also detected in the luminal pole of tubular epithelial cells of rats kidney. The data show that LPM of different mammalian species share several common glycoprotein antigens. These glycoproteins, that are also partly expressed in extrahepatic tissues, may represent plasma membrane structures conserved among mammalian species.
Animals↗
Are antimitochondrial antibodies in primary biliary cirrhosis induced by R(rough)-mutants of enterobacteriaceae?
Antimitochondrial antibody (AMA)-positive serum samples from 45 patients with primary biliary cirrhosis (PBC) and AMA-negative serum samples from patients with chronic liver diseases, systemic lupus erythematosus, or rheumatoid arthritis were studied by an immunoblot technique with mitochondria from bovine heart and pig kidney and with several strains of gram-negative bacteria as antigens after separation by sodiumdodecylsulphate polyacrylamide gel electrophoresis. Serum from patients with PBC recognised up to three mitochondrial antigens with molecular weights of 70 kD, 50 kD, and 42 kD. Equivalent patterns were found with bands at 70-80 kD and 50-52 kD with Enterobacteriaceae as antigens. AMA-reactive polypeptides were localised in the ribosomal and membrane fractions from Enterobacteriaceae but differed from known outer membrane proteins. Conversely, PBC-specific mitochondrial antigens at 70 kD and 50 kD were recognised by rabbit antisera against Salmonella minnesota Rb and Rc mutants but not by antisera against wild-type Enterobacteriaceae. Absorption experiments and two-dimensional immunoblotting studies confirmed that mitochondria and gram-negative bacteria share identical PBC-specific determinants. It seems that PBC-specific antigens are expressed in gram-negative bacteria and that these antigens may be immunogenic in mutants with defective polysaccharide synthesis. The data support the hypothesis of a bacterial aetiology for PBC.
Adult↗