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H Hutter

Publications and source records attributed to H Hutter.

45 records · Page 3Linked to original sources
PubMed1993

Disturbance of keratin homeostasis in griseofulvin-intoxicated mouse liver.

BACKGROUND: Alterations of the hepatocytic intermediate filament (IF) cytoskeleton, i.e., derangement and diminution of the keratin network and appearance of cytoplasmic aggregates of keratin-containing material, termed Mallory bodies, are characteristic features of human alcoholic hepatitis. Mallory bodies can be experimentally produced in mouse liver by chronic griseofulvin (GF) administration. GF intoxication of mice is, therefore, a suitable model to study the mechanisms of Mallory body formation and related cytoskeletal changes. EXPERIMENTAL DESIGN: To investigate the correlation between morphologic alterations of the keratin cytoskeletal network and the mRNA levels for liver keratins A (8) and D (18) in this pathologic situation immunohistochemical studies and northern blot analyses were performed. The amount of mRNA for both keratins was also analyzed by nuclease S1 protection assay. RESULTS: In GF-treated livers (4 months of treatment) an increase of mRNA for both liver keratins was found. This increase of mRNA was unexpected under these conditions, since in longterm GF-fed animals, the amount of keratin IFs was reduced as revealed by immunofluorescence and electron microscopy and by biochemical analysis of keratin proteins. In livers treated for 2 months with GF the IF meshwork seemed to be still intact, but the increase of RNA was already detectable indicating that alterations of keratin mRNA precede detectable morphologic alterations. When using this mRNA for in vitro translation experiments, strong keratin polypeptide spots could be detected by autoradiography of 2-dimensional gels. CONCLUSIONS: These results strongly suggest that in vivo under the conditions of GF intoxication posttranslational modifications, like phosphorylation, proteolysis and covalent cross-linking, could influence IF homeostasis and interfere with IF assembly. Increase of mRNA for liver keratins despite IF protein reduction might be due to negative feedback regulation.

Animals↗
PubMed1992

Modulation of protein composition of nuclear lamina. Reduction of lamins B1 and B2 in livers of griseofulvin-treated mice.

Chronic griseofulvin (GF) intoxication of mice leads to severe alterations of the hepatocytic intermediate filament cytoskeleton similar to that found in alcoholic hepatitis in humans (i.e., derangement and diminution of the keratin filament network and appearance of cytoplasmic aggregates of keratin-containing material, termed Mallory bodies). To investigate eventual alterations of nuclear lamins under these pathologic situations monoclonal antibodies were produced. One of these, GL-35, was directed to lamin B1 and lamin B2. Immunofluorescence microscopy revealed in GF-treated livers, in comparison to normal mouse livers, a highly reduced immunoreaction for lamins B1 and B2, whereas the staining for lamins A and C was unchanged. This reduction of both B-type lamins occurred before detectable alterations of keratin filaments and was reversible after cessation of GF intoxication. A diminished content of both B-type lamins in relation to lamins A and C in GF-intoxicated livers was also revealed by analysis of isolated nuclear envelopes on two-dimensional gels. Moreover, there was a clear predominance of more acidic isoelectric variants of lamins B1 and B2. In contrast to the reduced amount of B-type lamin proteins no reduction in the concentration of the mRNA for lamin B1 was found. For lamin B2 even an increase of mRNA was detected in GF-treated livers. These results indicate that GF not only interferes with expression of the keratin intermediate filament skeleton of hepatocytes but also leads to selective alterations of the nuclear lamins, most likely by posttranslational modifications of intermediate filament proteins.

Animals↗
PubMed1990

[Epidemic keratoconjunctivitis: treatment results during an epidemic].

150 patients with adenovirus type 8 infection where treated at random, in a prospective study. Based upon a quantifiable conjunctivitis severity score we tried to find out where there are differences in treatment. The best results were seen using polyvinylpyrrolidone-iodine (Betaisodona) although it could not prevent totally subepithelial corneal infiltrates. The combination of exogenous interferon alpha with polyvinylpyrrolidone-iodo-drops or trifluorothymidine-drops was less successful. We could not show any prophylactic effect of interferon on uninflamed fellow eyes. Treatment with vasoconstrictor did not show any therapeutic or prophylactic potency. This group of patients must be seen as a control group and the results of effective therapy should significantly differ from the results in this group. Topical corticosteroids should be reserved for severe symptomatic cases and those with iritis and pseudomembranous conjunctivitis. Giving topical corticosteroids in combination with antibiotics we did not find any influence on the incidence of subepithelial keratitis or the number of corneal infiltrates. The mean duration of acute keratoconjunctivitis using this therapy was longer than the mean duration in the control group with vasoconstrictor.

Acrylic Resins↗