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H Denk

Publications and source records attributed to H Denk.

At least 19 recordsLinked to original sources
PubMed1992

Distribution of cytokeratins, vimentin and desmoplakins in normal renal tissue, renal cell carcinomas and oncocytoma as revealed by immunofluorescence microscopy.

Forty-two renal cell carcinomas, one oncocytoma and normal renal tissue were studied for the presence of cytokeratins and vimentin. The investigations were performed by immunofluorescence microscopy applying a panel of mono- and polyclonal antibodies to intermediate filament proteins. In all tumours except chromophobic renal cell carcinoma (CRCC) and oncocytoma a co-expression of cytokeratins and vimentin could be shown. The intermediate filament expression was often, however, very heterogeneous particularly with respect to the distribution of cytokeratins and vimentin, to the clonality of the antibodies used and to the tumour areas studied. The latter could be impressively demonstrated by examining a whole tumour. In CRCC and oncocytoma all tumour cells expressed cytokeratins and, in addition, single tumour cells also expressed vimentin. In normal renal tissue we could show vimentin-positive epithelia of proximal and distal tubules, which is reported for the first time.

Adenoma↗
PubMed1992

Extended radical surgery against gastric cancer: low complication and high survival rates.

The present study examines survival benefits for 338 gastric cancer patients from radical surgical treatments, including radical lymphadenectomy of group 3 nodes and combined resection of infiltrated adjacent organs. Curative surgery, with no detectable residual tumor, was possible for 236 patients (69.8%). The radical surgical approach was constant in execution, with 330 of the 338 patients (97.6%) being operated upon by the same surgeon. The remaining patients were operated upon in a similarly radical manner which always included a lymphadenectomy of the N-3 region. Anastomotic leakage was observed in seven patients (3.0%). The postoperative mortality rate was 4.8% for total gastrectomy cases and 3.3% for subtotal gastrectomy cases. The actuarial five-year survival rate for patients receiving curative surgery was 50.0%. These low complication and high survival rates support the concept of extended radical surgery for gastric cancer.

Adenocarcinoma, Mucinous↗
PubMed1992

High amount of epsilon-(gamma-glutamyl)lysine cross-links in Mallory bodies.

Alcoholic hepatitis, the most severe form of alcoholic liver disease, is associated with inflammation, liver cell necrosis, and the appearance of Mallory bodies (MBs) in hepatocytes. Identical MBs can be experimentally induced in mouse livers by chronic griseofulvin or 3,5-diethoxycarbonyl-1,4-dihydrocollidine treatment. MBs are filamentous cytoplasmic inclusions containing insoluble high molecular weight protein material. Covalent polymerization of intracellular proteins may occur through formation of epsilon-(gamma-glutamyl)lysine cross-links catalyzed by Ca(2+)-dependent transglutaminases. Therefore, isolated experimentally-induced MBs were analyzed for the presence of epsilon-(gamma-glutamyl)lysine bonds. Highly purified MBs contained 19.7 nmole (griseofulvin-induced) and 14.4 nmoles (3,5-diethoxycarbonyl-1,4-dihydrocollidine induced) of isodipeptide linkage, respectively, per mg of protein. These results suggest that transglutaminase-induced cross-linking of proteins plays a major role in MB formation.

Animals↗
PubMed1992

Common epitopes of human and murine Mallory bodies and Lewy bodies as revealed by a neurofilament antibody.

The antibody SMI 31, which is directed against a phosphorylated epitope, associated with neurofilaments and recognizes Lewy bodies in brains of patients with Parkinson's disease (Bancher C, Lassmann H, Budka H, Jellinger K, Grundgke-Iqbal I, Iqbal K, Wiche G, Seitelberger F, Wisniewski H: J Neuropathol Exp Neurol 1:81, 1989), decorated in immunofluorescence microscopy Mallory bodies (MBs) present in livers of mice chronically treated with griseofulvin and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. In immunoblots it recognized very acidic MB components in a molecular weight range between 55 and 69.5 kilodaltons in addition to poorly soluble high molecular weight material. Moreover, an antibody to tau protein showed similar reactivities in immunofluorescence microscopy and immunoblotting experiments. Both antibodies also stained MBs in human liver with alcoholic hepatitis. These observations support and extend earlier findings which indicate that several intermediate filament-related cellular inclusion bodies, including MBs, share a variety of morphologic, structural and antigenic features. They also suggest the involvement of tau or tau-like proteins in MB formation.

Animals↗
PubMed1992

Alcoholic liver disease. Parenchyma to stroma relationship in fibrosis and cirrhosis as revealed by three-dimensional reconstruction and immunohistochemistry.

Severe ethanol-induced liver damage is characterized by fibrous dissociation of liver cell plates leading to many apparently isolated hepatocytes. Three-dimensional reconstruction, however, revealed hepatocytes that were surrounded by connective tissue as endpoints of "parenchymal pillars" or in association with liver cell plates and bile ductules. Double immunofluorescence studies displayed the expression of cytokeratin (CK) 7 in bile ducts, including bile ductules, but also in some hepatocytes still organized in liver cell plates. The other bile duct, typical CK, namely CK 19, was only detectable in few hepatocytes. However, the expression of CK 7 and/or CK 19 was less frequent in hepatocytes that were closely associated with bile ductules. CK 7 and CK 19 were also found in some, but not all, Mallory bodies. These observations indicate that the expression of these two CKs is neither related to a transformation of hepatocytes to bile duct-like structures ("ductal metaplasia") nor to the formation of Mallory bodies. Furthermore, double immunofluorescence studies revealed small groups of hepatocytes and bile ductules that were encircled by basement membrane material, thus suggesting the formation of "secretory units."

Aged↗
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↗
PubMed1991

Simultaneous resection of colorectal carcinoma and synchronous liver metastases in a district hospital.

Of 491 patients operated for carcinomas of the colon or rectum between 1984 and 1989, 106 were tumour stage IV, U.I.C.C.(Dukes' 'D') at time of operation. In 22 of these cases a radical resection of the carcinoma of the colon or rectum and of synchronous liver metastases was performed simultaneously. In 20 patients the metastases were confined to one, in two they were found in both hepatic lobes. In one case a solitary metastasis of the lower lobe of the right lung was resected additionally. Three right-sided hemihepatectomies, one extended right hemihepatectomy, five left-sided hemihepatectomies, three left-sided lateral segmentectomies, seven atypical segmental resections and three wedge resections were performed. The mean operation time for the radical resection of the carcinomas of the colon or rectum as well as of the liver metastases was 3.5 (3-5.2)hours. An average of 3 (0-9) blood units were needed intraoperatively. The major liver resections were performed in complete normothermic vascular ischaemia using the finger fracture method. The time of ischaemia ranged between 8 and 25 min. Only 1 of 22 patients died postoperatively (30 days postoperative hospital mortality rate 4.5%). Five of 17 patients were free of tumour 2 years after operation. Eight of 22 were alive 2 years after operation (non-age corrected 2-year survival rate 36.4%), 2 of them are alive more than 5 years after treatment. Our results demonstrate that simultaneous resection of colon or rectum carcinoma and of synchronous (resectable) liver metastases can be performed successfully, even in a district hospital.

Austria↗
PubMed1991

Enzyme-histochemical studies of griseofulvin-intoxicated mouse livers.

Enzyme-histochemical studies were conducted on livers of mice chronically fed griseofulvin (GF) in order to produce Mallory bodies (MBs) in hepatocytes. The development of MBs is associated with derangement of the immunohistochemically detectable intermediate filament (IF) cytoskeleton of the cytokeratin (CK) type, although no strict correlation between appearance or involution of MBs and the cytoskeletal alterations exists. Since the function of the IF cytoskeleton and the relationship of its disturbance to cell injury is unknown, the aim of the present study was to correlate the activities of several key enzymes of cellular metabolic pathways with the disturbance of the cytoskeleton architecture. For that purpose enzyme-histochemistry in combination with immunohistochemical CK-IF stainings were performed on identical sections. In GF-intoxicated mouse livers the normal topography of enzyme activities was disturbed, but no strict colocalization of enzymatic and cytoskeletal changes was found. Glucose-6-phosphatase, a microsomal enzyme involved in glucose output and gluconeogenesis, showed elevated activity in MB-free hepatocytes with diminished immunostainable CK-IF cytoskeleton refuting the concept of a disability of those cells to export glucose. It could indeed indicate that those cells without MBs are in the state of recovery. However, these cells could also resemble "hyperactive foci". Glycogen was decreased in MB-containing hepatocytes with disturbed cytoskeleton, and this feature favours the assumption of cell degeneration. On the other hand, the mitochondrial marker enzymes, i.e. succinate dehydrogenase, cytochrome-c-oxidase and 3-hydroxybutyrate dehydrogenase, remained unchanged in altered hepatocytes. Alkaline phosphatase activity at the canalicular pole of GF-intoxicated hepatocytes was elevated, indicating cholestatic features associated with this disorder. However, since altered hepatocytes did not show impairment of oxido-reductase activities, a severe impairment of bile secretion as a consequence of cell damage is unlikely. Unchanged or even increased ATPase activity of altered hepatocytes also indicated their sustained metabolic abilities. The results presented provide indirect evidence that hepatocytes with disturbed IF cytoskeleton do not significantly differ from normal cells with respect to oxidative metabolism, fatty acid synthesis and gluconeogenesis. This suggests that alterations of the IF cytoskeleton associated with GF intoxication and MB formation have no significant adverse influence on the metabolic functions of liver cells, as far as can be assessed by evaluation by enzyme-histochemical staining of several key enzymes.

Animals↗
PubMed1991

Changes of cytokeratin filament organization in human and murine Mallory body-containing livers as revealed by a panel of monoclonal antibodies.

Mallory bodies (MBs) are characteristics morphologic features of alcoholic hepatitis and can be produced in mouse hepatocytes by chronic griseofulvin (GF) intoxication. The formation of MBs, which share some immunological, biochemical, and ultrastructural features with cytokeratin (CK) filaments of normal liver, is accompanied by derangement and even loss of the CK cytoskeleton of hepatocytes ("empty cells") as revealed by immunofluorescence microscopy. To clarify whether this diminution or lack of CK-related staining of MB-containing hepatocytes was due to loss of CK filaments or changes in antigenicity or accessibility of antigenic determinants immunohistochemical studies using a battery of monoclonal and polyclonal CK antibodies were performed. It could be shown that all these antibodies directed against different CK polypeptide components and antigenic determinants of CKs revealed a highly reduced or even undetectable cytoplasmic CK meshwork in most cells with fully developed large MBs. In the light of our present knowledge of the organization of CK intermediate filaments, these results indicate that the phenomenon of the "empty cells" reflects a diminution of CK meshwork rather than altered antigenic determinants.

Animals↗
PubMed1991

High molecular weight components are main constituents of Mallory bodies isolated with a fluorescence activated cell sorter.

Mallory bodies (MBs) are cytoplasmic filamentous aggregates containing cytokeratin (CK) material. They occur in hepatocytes of patients with alcoholic liver disease (i.e., alcoholic hepatitis) and can also be induced experimentally in mice by chronic griseofulvin intoxication. To further investigate components and mechanisms involved in MB formation, a new method for MB purification was established. MBs present in a liver homogenate of griseofulvin-fed mice were labeled with a murine monoclonal antibody specific for MBs and a second fluorescein isothiocyanate-conjugated (anti-mouse IgG and IgM) antibody and subsequently isolated by two sequential sorting procedures using a fluorescence activated cell sorter (FACS). Purity of MB isolates was over 90% as revealed by computer analysis of sorting signals and fluorescence and electron microscopy. Electrophoretic separation on sodium dodecyl sulfate-polyacrylamide gels revealed three MB-related polypeptides with apparent molecular masses of 48, 55, and 65 kilodaltons but most of the highly purified MB material did not enter the gel or remained at the interphase between stacking and resolving gels. Western blotting with CK-specific antibodies showed the presence of CK epitopes in the high molecular weight MB material, which has a similar amino acid composition as normal liver CKs. These results establish that very high molecular weight material is the main constituent of MBs and suggest that a post-translational modification of CKs by covalent crosslinks is a principal mechanism of MB pathogenesis.

Amino Acids↗
PubMed1991

Modulation of alpha smooth muscle actin and desmin expression in perisinusoidal cells of normal and diseased human livers.

It has been suggested that perisinusoidal liver cells (PSC) play a pivotal role in the pathogenesis of fibrocontractive changes. Using light and electron microscopic immunolocalization techniques, a series of 207 normal and pathologic human liver specimens were evaluated for the expression of alpha smooth muscle (SM) actin and desmin in this and other nonparenchymal cell types. In normal adult liver tissue, PSCs were practically devoid of desmin and exceptionally stained for alpha-SM actin, whereas this actin isoform frequently was encountered in PSCs from the embryonic to the adolescent period. A broad spectrum of pathologic conditions was accompanied by the presence of alpha-SM actin containing PSCs; these were detected preferentially in periportal or perivenular zones according to the predominant location of the underlying hepatocellular damage. The occurrence of this PSC phenotype generally was associated with fibrogenesis and was in some cases detected earlier than overt collagen accumulation. Fibrous bands subdividing liver tissue in cirrhosis and focal nodular hyperplasia, as well as desmoplastic reaction to malignant tumors, contained alpha-SM actin-rich cells admixed with variable proportions of cells coexpressing desmin. In end stages, this population was less numerous than in active fibrotic or cirrhotic processes. Using immunogold electron microscopy, alpha-SM actin was localized in microfilament bundles of typical PSCs. Our results are compatible with the assumption that the appearance of alpha-SM actin and desmin-expressing myofibroblasts results at least in part from a phenotypic modulation of PSCs.

Actins↗
PubMed1990

Fate of Mallory body-containing hepatocytes: disappearance of Mallory bodies and restoration of the hepatocytic intermediate filament cytoskeleton after drug withdrawal in the griseofulvin-treated mouse.

Mallory bodies are characteristic morphological features of alcoholic hepatitis in man and can be produced in the mouse by chronic griseofulvin intoxication. The appearance of Mallory bodies in hepatocytes is associated with derangement of the cytokeratin intermediate filament cytoskeleton, at least as revealed by immunofluorescence and suggested by immunoelectron microscopy. Immunohistochemical studies were performed to answer the question whether Mallory body formation and cytoskeleton alterations finally lead to cell death or are reversible phenomena. Chronically griseofulvin-intoxicated mice killed at different stages of recovery on a normal diet served as experimental animals. It could be shown that (a) Mallory bodies are very durable structures and are found for up to 6 mo after griseofulvin withdrawal as a result of persistence and neoformation; (b) new Mallory bodies can appear even several months after cessation of griseofulvin feeding; (c) Mallory body formation and cytoskeletal changes by themselves do not lead to irreversible cell damage; (d) the cytoskeletal changes are reversible within 7 mo after griseofulvin withdrawal; (e) a dissociation between disappearance of Mallory bodies and restoration of a regularly immunostained cytoplasmic cytokeratin meshwork is observed.

Animals↗
PubMed1990

High molecular weight component of Mallory bodies detected by a monoclonal antibody.

To identify Mallory body (MB) constituents, monoclonal antibodies to murine MBs induced by long-term griseofulvin (GF) feeding were produced. One of these, antibody MM 120-1, specifically reacted in immunofluorescence microscopy with MBs in all developmental stages but not with other cell structures of human and mouse liver and other organs. The MM 120-1 antigen was present in murine MBs induced by griseofulvin or 3,5-diethoxycarbonyl-1,4-dihydrocollidine feeding and also in human MBs in livers of patients with alcoholic hepatitis. In immunoblots, the MM 120-1 antigen was detectable in the high molecular weight fraction of MB preparations, most of which remained in the well and at the interphase between stacking and resolving gel. No reactivity with cytokeratin polypeptides of different conformational states (i.e., isolated cytoker atin components A and D, heterotetramers A2D2, reconstituted intermediate filaments) was found. It is concluded that the antibody MM 120-1 is a highly specific and sensitive marker for murine and human MBs recognizing a high molecular weight nonkeratin component. This component could play a central role in the pathogenesis of MBs.

Animals↗
PubMed1990

[Cytoskeleton--function and pathology: studies on the pathology of the intermediate filament cytoskeleton of liver cells].

Microfilaments, microtubules and intermediate filaments (IF) are major filamentous components of the cytoskeleton and play a role in the modulation of cell shape, in cellular movements, cellular stability, intracellular organisation as well as cell-to-cell and cell-to-stroma interactions. Particular interest was concentrated in the last few years on IF because of their cell type-specificity and, consequently, their suitability as cell markers in diagnostic pathology. Despite their apparent stability, IF are dynamic structures which may be modified under pathologic conditions. In recent years, pathologic alterations related to the IF cytoskeleton have been described in a diversity of chronic and degenerative disorders, including alcoholic hepatitis and neurologic diseases (e.g. M. Alzheimer, M. Parkinson). Our studies were particularly devoted to the elucidation of the pathogenesis of severe alcoholic liver injury (alcoholic hepatitis), which is associated with inflammation, liver cell degeneration and necrosis and morphologically characterized by the appearance of cytoplasmic hyaline inclusions (i.e., Mallory bodies). In the present review morphologic, immunologic and biochemical studies on nature and pathogenesis of Mallory bodies are summarized. Moreover, similarities between Mallory bodies and other cytoskeleton-related inclusion bodies suggest common routes of pathogenesis. Consequently, studies along these lines may not only lead to the understanding of mechanisms involved in alcoholic injury but may also provide information on general principles of cell damage as well as on regulation and function of the IF cytoskeleton.

Animals↗
PubMed1979

Effect of protease pretreatment on immunomorphologic demonstration of hepatitis-B-surface antigen in conventional paraffin-embedded liver biopsy material: quantitative evaluation.

The effect of protease pretreatment on the demonstration of hepatitis-B-surface antigen by immunofluorescence (IF) and the unlabeled peroxidase-antiperoxidase technique (PAP) in conventionally processed (formalin-fixed, paraffin-emmbedded) liver biopsy material was quantitatively assessed by microphotometry. Protease digestion significantly enhances the intensity of specific staining by both methods, and, in addition, suppresses non-specific background fluorescence. The sensitivity of the immunomorphologic test is significantly enhanced, and antigen in low amounts, for example hepatitis-B-surface antigen associated with liver cell membrane ('membrane' staining), is easily detected.

Animals↗