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R Moll

Publications and source records attributed to R Moll.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Cytokeratins as markers of differentiation. Expression profiles in epithelia and epithelial tumors].

Intermediate filaments (IFs; diameter, about 10 nm) are cytoplasmic cytoskeletal structures found in most vertebrate cells. Their protein subunits comprise a large multi-gene family of related proteins, which make it possible to divide IFs into seven separate classes whose expression is cell-type-dependent. The most important IF classes are cytokeratin (CK) filaments (epithelial cells), vimentin filaments (mesenchymal cells), desmin filaments (muscle cells), glial filaments (astrocytes), and neurofilaments (nerve cells). As the specificity of expression of IF proteins is retained in malignant tumors, they are suitable as histological markers of differentiation (tumor markers). The protein subunits of the epithelial CK filaments are unusually diverse, and within the various types of epithelia, their expression is differentiation specific. Until recently, the catalog of human CKs comprised 19 related, yet distinct polypeptides (CKs 1-19; Moll et al., 1982a); CK 20 can now be added to this list. On the basis of sequence relationships, two CK subfamilies can be delineated (CKs 9-20 = type I; CKs 1-8 = type II). Any given epithelial cell exhibits a characteristic, differentiation-dependent combination of two or more CK polypeptides, with type-I and -II polypeptides always occurring in stoichiometric amounts (i.e., as "pairs"), because the basic structural unit of the CK filaments is a heterotypical tetramer complex. On the basis of their main tissue distribution patterns, it is possible further to subdivide these polypeptides into CKs typical of stratified squamous epithelia (CKs 1-6, 9-17) and those typical of simple columnar epithelia (CKs 7, 8, 18-20); these CKs exhibit differential expression patterns in the various types of squamous and columnar epithelia. The actual characterization of the novel CK 20 as a CK initially proved to be rather difficult, as this cytoskeletal protein, which can be biochemically isolated from cells of the intestinal epithelium (M(r) 46,000; previously called "IT protein"), exhibits no reaction with numerous well-known CK antibodies in Western blots. However, a series of other characteristics typical of CKs could be demonstrated. Thus, IT protein was found, in vitro (nitrocellulose-blot binding test, native gel electrophoresis), to for heterotypical complexes with the type-II CK 8, and these complexes were able to reconstitute themselves into typical IFs in vitro. Chymotrypsin-cleaving experiments revealed the presence of a resistant core fragment (M(r) 38,000), indicating a alpha-helical "coiled-coil" conformation typical of IFs.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

[Uroplakin III, a specific membrane protein of urothelial umbrella cells, as a histological markers for metastatic transitional cell carcinomas].

We have investigated, by immunohistochemical staining of various paraffin-embedded carcinoma sections, the tissue-specific expression of uroplakin III--a recently characterized constituent glycoprotein (47 kD) of the asymmetrical unit membrane which forms plaques on apical surface of urothelial umbrella cells. The apical membrane pattern of normal urothelial umbrella cells was in part maintained in papillary transitional cell carcinomas (TCCs). In addition, in both papillary and invasive TCCs, variously sized lumina exhibited positive membrane staining of uroplakin III. In some cases, basal cell membrane staining was seen. Positive reactions (which sometimes were very focal) were noted in 16/18 papillary non-invasive TCCs (89%), 21/37 invasive TCCs (57%) and 12/15 TCC metastases (80%). Non-TCC carcinomas of different origin (n = 63) were consistently negative. These results show that uroplakin III may serve as a useful marker for TCCs, revealing specific urothelial differentiation features to be expressed in such tumors even after metastasis. This marker, while of only intermediate sensitivity, is highly specific, thus opening interesting histodiagnostic possibilities in the case of unclear carcinoma metastases.

Biomarkers, Tumor↗
PubMed1993

Ultrastructural appearance and cytoskeletal architecture of the clear, chromophilic, and chromophobe types of human renal cell carcinoma in vitro.

The clear, chromophilic, and chromophobe types of human renal cell carcinoma have been defined as distinct morphological entities and can be clearly separated by differences of ultrastructural appearance, cytoskeletal architecture, enzyme synthesis, and cytogenetic aberrations. In this report, the cytomorphological aspects of these tumor types are compared in vitro, showing that essential ultrastructural and cytoskeletal characteristics of each tumor type are expressed even after prolonged in vitro cultivation. The pattern of intermediate filament proteins of each tumor type was preserved in vitro, permitting the separation of exclusively cytokeratin-positive chromophobe tumor cells from clear and chromophilic tumor cells with a co-expression of vimentin and cytokeratins. In vitro, the chromophobe tumor cells continued to exhibit abundant cytoplasmatic microvesicles and sparsely distributed "studded" vesicles, which are known to be characteristic features of this tumor type in vivo. This observation confirmed the structural similarity of the chromophobe cell to the 'intercalated cell' of the cortical collecting duct and provided further evidence for the histogenetic derivation of this tumor subtype from the collecting duct system.

Carcinoma, Renal Cell↗
PubMed1993

Differential loss of E-cadherin expression in infiltrating ductal and lobular breast carcinomas.

The epithelial-specific cell-cell adhesion molecule E-cadherin was analyzed immunohistochemically on tissue sections of 89 human primary infiltrating breast carcinomas, using monoclonal antibodies 6F9 (for cryostat sections) and 5H9 (for cryostat and paraffin sections). The tumors included 41 well and moderately differentiated infiltrating ductal carcinomas (IDCs) most of which (78%) showed strong linear staining at the cell borders at a level, as high as luminal cells of normal mammary glands. The 26 poorly differentiated, more highly malignant IDCs examined also were all positive for E-cadherin, although a higher proportion of them (54%) showed reduced staining, which was heterogeneous and dotted over the cell borders. In contrast, 19 of 22 infiltrating lobular carcinomas (ILCs), which were either of the dispersed (classical), solid, or the mixed type, did not express E-cadherin, whereas three cases showed weak staining. In situ lesions of ILCs and pure lobular carcinoma in situ (four cases) were all E-cadherin negative, whereas intraductal carcinomas (11 cases) exhibited mostly strong staining. The results were confirmed by Western blotting. The data indicate that loss of E-cadherin expression is an early event in the formation of the lobular type of breast carcinomas. The absence of E-cadherin signifies a partial loss of epithelial differentiation and may account for the extended spread of lobular carcinoma in situ and the peculiar diffuse invasion mode of ILC. The generation of dedifferentiated IDCs can only in part be correlated with reduced expression of the intercellular adhesion molecule E-cadherin. Other factors are obviously also involved during invasion of this carcinoma type.

Adult↗
PubMed1992

Morphological, immunohistochemical and biochemical characterization of 6 newly established human ovarian carcinoma cell lines.

Six permanent human tumor cell lines (OV-MZ-1 to 6) were established from 6 patients with serous adenocarcinomas of the ovary. These cell lines were derived from both solid tumors and ascites, from pre-treated and untreated patients, and are available over a range of in vitro passage numbers. The tumor cells grow as monolayers and develop foci of "piled-up' cells in confluent cultures. Flow cytophotometry showed that all the lines exhibited DNA hyperdiploidy with DNA tetraploidy in one cell line and DNA aneuploidy in the other cell lines. The mean population doubling time ranged from 24 to 52 hr. Transmission electron microscopy demonstrated that the tumor cells of all cell lines exhibited features of epithelial differentiation such as desmosomes and intracellular gland-like lumina. Immunocytochemical analysis showed that the co-expression of cytokeratins and vimentin, which is a feature of ovarian serous cystadenocarcinomas in situ, was fully preserved in the majority of cell lines. The main cytokeratin polypeptides expressed were numbers 7, 8, 17, 18 and 19. The tumor-associated antigen CA-125, but not CEA, was shed in the culture supernatant. This was in accordance with FACScan analysis of the cell lines and the level of CA-125 and CEA in the patients' serum. The estrogen and progesterone receptors were negative both in the cell lines and in the original tumors. These new ovarian carcinoma cell lines will be valuable models for further investigations into a variety of biological properties.

Adult↗
PubMed1992

Changes in cytokeratin expression accompany squamous metaplasia of the human respiratory epithelium.

To determine the characteristics of metaplastic changes of the nasal respiratory epithelium, the distribution of individual cytokeratins (CKs) was studied immunohistochemically and by two-dimensional gel electrophoresis. The authors define four types of changes of the normal pseudostratified columnar epithelium: (1) transitional pseudostratified epithelium (first unusual CK.: no. 13); (2) stratified columnar epithelium (increased expression of CKs 4 and 13; CKs 7, 8, 18 and 19 reduced); (3) stratified squamous epithelium, nonkeratinized (appearance of CK 16); and (4) stratified squamous epithelium, keratinized (expression of CKs 1 and 10, variable CK5 and 14 patterns in basal cells). These phenotypes were found simultaneously within single specimens, resulting in apparent overall variability in the immunohistochemical staining patterns. Spatially, changes in CK expression towards "normal" parts were not abrupt but rather gradual. Biochemical data confirmed the immunohistochemical findings and added CK 6 to the pattern of altered nasal mucosa. The findings of this study suggest a stem cell metaplasia in the nasal epithelium which is based on its inherent bimodal developmental programme. A gradual loss of normal respiratory epithelial differentiation, as seen by the loss of CKs 7, 8, and 18, was paralleled by the appearance of squamous epithelial type CKs, e.g. the expression of CKs 1, 10 and 13. Basal cell types CKs 5, 14, 17 and 19 were maintained during this process. Implications of these results for general concepts of CK expression in the metaplastic process are discussed.

Adolescent↗
PubMed1992

Characterization of human cytokeratin 2, an epidermal cytoskeletal protein synthesized late during differentiation.

Among the more than 30 different human proteins of the cytokeratin (CK) group of intermediate filament (IF) proteins, the significance of the epidermal polypeptide CK 2 (Moll et al., 1982, Cell 31, 11-24) has been repeatedly questioned in the literature. Here, we show, by in vitro translation and protein gel electrophoresis, that human epidermis from various body sites does indeed contain relatively large amounts of mRNA encoding a distinct polypeptide comigrating with native epidermal CK 2. We also report the isolation of a cDNA clone encoding the complete sequence of CK 2, which is a type II CK different from--but related to--epidermal CKs 1 and 5 on the one hand and corneal CK 3 on the other. The mRNA of approximately 2.6 kb encodes a polypeptide of 645 amino acids and M(r) 65,852, in good agreement with the value of 65.5 kDa previously estimated from gel electrophoresis. This human CK, the largest so far known, displays several features typical of CKs of stratified epithelia, including numerous repeats of glycine-rich tetrapeptides in the head and tail domains. Northern blot and in situ hybridizations have shown that CK 2 is expressed strictly suprabasally, usually starting in the third or fourth cell layer of epidermis, and this was confirmed at the protein level by immunohistochemistry using CK 2-specific antibodies. The protein has been detected as a regular epidermal component in skin samples from different body sites, albeit as a minor CK in "soft skin" (e.g., breast nipple, penile shaft, axilla), but not in foreskin epithelium and in other epithelia, in squamous metaplasias and carcinomas, or in cultured cell lines derived therefrom. We propose that CK 2 is a late cytoskeletal IF addition synthesized during maturation of epidermal keratinocytes which probably contributes to terminal cornification.

Amino Acid Sequence↗
PubMed1992

Changes of expression of intermediate filament proteins during ontogenesis of eccrine sweat glands.

The intermediate filament expression in fetal and adult human eccrine sweat glands was studied by immunoperoxidase microscopy performed on cryostat sections using monoclonal antibodies against various cytokeratins (CK), vimentin, and actin. In palmar skin of 14-week-old fetuses, the early dermal cords showed a primitive CK pattern similar to that of epidermal basal cells. From week 15 on (distal finger skin), inner cells of the proximal (ductal) portion of the glandular anlagen expressed CK 1/10/11 and 19 (markers of adult eccrine ductal luminal cells). In addition, CK 4 was expressed in ductal luminal cells mainly in the fetal period. In the distal portion of the sweat gland anlagen the increased or new expression of the simple-epithelium-type CK 7, 8, 18, and 19 was detected at week 15, indicating the onset of the secretory differentiation pathway. Two subsegments of the prospective secretory portion could be distinguished (elongated part and end bud). Interestingly, in fetuses, most secretory portion cells co-expressed vimentin in addition to CK. From week 22 on, peripheral cells of the secretory portion were stained for CK 17 and smooth-muscle-type actin, suggesting myoepithelial differentiation. In newborn and adult eccrine glands, secretory cells expressed mainly CK 7, 8, 18, and 19, whereas myoepithelial cells were conspicuous by their co-expression of certain CK (including CK 5 and 17), vimentin, and smooth-muscle-type actin and sometimes even glial filament protein (GFP), similar to myoepithelial cells of other glands. These results throw further light onto the complex processes of fetal development of eccrine sweat glands and their cellular diversification. The possible biologic significance of the differential CK expression in the various glandular cell types is discussed.

Adult↗
PubMed1992

Early development of human Merkel cells.

Human fetal Merkel cells are now generally considered to be epidermal derivatives. Previous studies using antibodies against the simple epithelial cytokeratins (CKs), 8 and 18, have demonstrated the presence of these cells in the epidermis at as early as fetal week 10 to 12. Using antibodies against CK 20 whose expression within the skin is restricted to Merkel cells, we applied immunofluorescence and immunoperoxidase microscopy to analyze earlier embryonic and fetal human skin (wk 7 to 9). We were able to demonstrate the first Merkel cells at as early as fetal wk 8, i.e., at the same time as the epidermis starts to develop an intermediate, third layer, characterized by the expression of CKs 1, 10, and 11. Most of these early Merkel cells were localized above the basal layer. Their shape was round to oval, dendrites being infrequent and short. At fetal wk 9, Merkel cells were considerably more numerous. These results persuasively argue for a much earlier fetal development of Merkel cells within the epidermis than previously thought. A hypothesis concerning the differentiation of Merkel cells from embryonic basal keratinocytes is discussed.

Antibodies, Monoclonal↗
PubMed1992

Cytokeratin 20 in human carcinomas. A new histodiagnostic marker detected by monoclonal antibodies.

The authors have recently identified a new cytokeratin (CK) polypeptide, CK 20, whose expression is almost entirely confined to the gastric and intestinal epithelium, urothelium, and Merkel cells. Seven monoclonal antibodies (MAbs) specific for CK 20 were raised and characterized by applying immunoblotting and immunocytochemical screening. All of them reacted on frozen tissue sections. A further MAb, IT-Ks20.8, recognized CK 20 in sections of formalin-fixed, paraffin-embedded tissue samples. A total of 711 cases of primary and metastatic cancer, mostly carcinomas, were analyzed immunohistochemically for CK-20 expression, using CK-20 specific guinea-pig antibodies and MAbs. The expression spectrum of CK 20 in carcinomas resembled that seen in the corresponding normal epithelia of origin. CK-20 positivity was seen in the vast majority of adenocarcinomas of the colon (89/93 cases), mucinous ovarian tumors, transitional-cell and Merkel-cell carcinomas and frequently also in adenocarcinomas of the stomach, bile system, and pancreas. Most squamous cell carcinomas in general and most adenocarcinomas from other sites (breast, lung, endometrium), nonmucinous tumors of the ovary, and small-cell lung carcinomas were essentially or completely negative. The authors propose to use CK 20 as a diagnostic marker valuable in distinguishing different types of carcinomas, notably when presenting as metastases.

Animals↗
PubMed1991

Purification and characterisation of an archaebacterial succinate dehydrogenase complex from the plasma membrane of the thermoacidophile Sulfolobus acidocaldarius.

A succinate dehydrogenase complex was isolated in a three-step purification from plasma membranes of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius. It consists of four subunits: a, 66 kDa; b, 31 kDa; c, 28 kDa and d, 12.8 kDa. In the 141-kDa native protein, the four subunits are present in an equimolar stoichiometry. The complex contains acid-non-extractable flavin, iron and acid-labile sulphide. Maximal succinate dehydrogenase activities were recorded at pH 6.5, which coincides with the internal pH of Sulfolobus cells. The temperature optimum of 81 degrees C defines the Sulfolobus succinate dehydrogenase as a thermophilic enzyme complex. The Km for succinate was found to be 1.42 mM (55 degrees C). Similar to the mitochondrial soluble succinate dehydrogenase, this enzyme is capable of transferring electrons to artificial electron acceptors, for instance phenazine methosulfate, N,N,N',N'-tetramethyl-p-phenylenediamine and ferricyanide. In contrast to the mitochondrial succinate dehydrogenase, the archaebacterial enzyme reduces 1,4-dichloroindophenol also in the absence of phenazine methosulfate. Caldariella quinone, the physiological electron mediator in the Sulfolobus respiratory chain, was only slowly reduced under adjusted conditions. The succinate--phenazine methosulfate-(1,4-dichloroindophenol) oxidoreductase of the isolated complex was strongly inhibited by tetrachlorobenzoquinone. In plasma membranes the complex reduces molecular oxygen in a cyanide-sensitive reaction. Polyclonal Sulfolobus anti-a antibodies crossreacted with 66-67-kDa polypeptides from membranes of Thermoplasma acidophilium, Sulfolobus solfataricus and beef heart submitochondrial particles.

Cell Membrane↗
PubMed1991

Comparative cytokeratin analysis of sweat gland ducts and eccrine poromas.

Human eccrine sweat gland ducts and benign and malignant eccrine poromas were studied for the expression of various cytokeratins (CK) and vimentin by applying immunoperoxidase and immunofluorescence microscopy to frozen or paraffin-embedded sections, and using two-dimensional gel electrophoresis and immunoblotting. In acrosyringia and dermal eccrine ducts, the luminal cells exhibited intense staining for CKs 1/10/11 and 19. The periluminal cell layers of acrosyringia contained CKs 1/10/11, while CK 5 was absent. In contrast, the basal cell layer of dermal ducts was only positive with the antibody against CK 5, i.e. a pattern resembling that seen in epidermal basal cells. CK 9 was detected only in keratinocytes peripherally surrounding acrosyringia. In benign poromas, gel electrophoresis revealed that CKs 5 and 14 were predominant, with CKs 6, 16 and 17 being minor components. At the immunohistochemical level CKs 1/10/11 and 19 could be further detected with varying frequency in scattered or clustered cells and/or duct-like structures. Occasionally, CK 9-positive cells were observed. Malignant poromas displayed a similar overall gel-electrophoretic pattern. Their immunohistochemical staining patterns were also similar to (albeit rather more variable than) those seen in benign poromas. Our results show that, with respect to their CK expression pattern, the majority of poroma cells resemble the basal cells of both the dermal ducts and the epidermis, while only minor and variable subpopulations acquire features present in ductal/acrosyringial luminal cells that would be indicative of poral differentiation. Thus, the matrix cells of poromas seem to be most closely related to basal cells located at the transition between the glandular epidermal ridge and dermal eccrine duct, being in no way analogous to the cells of the adult acrosyringium above the basal cell level.

Adenoma, Sweat Gland↗
PubMed1991

Autosomal dominant polycystic kidney disease--in vitro culture of cyst-lining epithelial cells.

The major form of autosomal dominant polycystic kidney disease (ADPKD) in humans is linked to the PKD1 gene on chromosome 16p. The identity of the gene and the underlying pathogenetic mechanisms are not yet defined. Cyst-lining epithelial cells derived from a polycystic kidney were successfully grown in culture and designated MZ-PKD-1 cells. By linkage analysis, the related pedigree of the nephrectomized patient could be linked to the PKD1 gene on chromosome 16p. Thus, these cells exhibit the genotype of a mutated PKD1 gene and represent an in vitro culture model for ADPKD involving chromosome 16p. The antigenic phenotype was characterized immunohistologically by epithelial differentiation antigens and markers of individual nephron segments. An essentially identical antigenic pattern of proximal tubular cells was observed both in vitro and in fresh frozen tissue. Electron microscopy showed the formation of a microvillous-like coating. During growth phases in vitro successive changes in the cell shape were observed. MZ-PKD-1 cells exhibited a limited lifespan ending in replicative senescence. Northern blot analysis of kidney-growth-related genes, c-myc, TGF-alpha, TGF-beta 1, and EGF receptor revealed abundant expression of all of these genes in MZ-PKD-1 cells.

Antibodies, Monoclonal↗
PubMed1991

Complexity of expression of intermediate filament proteins, including glial filament protein, in endometrial and ovarian adenocarcinomas.

The expression patterns of intermediate filament proteins of primary and metastatic endometrial (n = 18) and ovarian (n = 24) adenocarcinomas were analyzed by immunocytochemistry using a panel of specific antibodies and by gel electrophoresis of cytoskeletal preparations, followed by immunoblotting. All cells of all endometrial adenocarcinomas studied contained the "simple epithelial"-type cytokeratins (CKs) 8, 18, and (mostly) 19, with variable numbers of cells also positive for CK 7 and vimentin. In addition, most of these tumors contained individual cells or groups of cells that were positive for the stratification-related CKs 4, 5, 6, 13, 14, and 17. The latter CKs were often associated with squamous cell foci, but were also found in some single (nonsquamous) tumor cells, indicative of early stages of squamous cell differentiation. Ovarian carcinomas of various histologic types and grades contained predominantly CKs 7, 8, 18, and 19. Serous, endometrioid, and anaplastic tumors, but not mucinous and clear cell tumors, also contained minor amounts of stratification-related CKs in variable combinations, mostly including CK 4. In all tumor types except mucinous tumors, vimentin was consistently detected in variable proportions of tumor cells which, however, were rather low in anaplastic carcinomas. Surprisingly, glial filament protein was detected in a minor proportion (< or = 20%) of tumor cells in seven of 14 serous and endometrioid ovarian carcinomas and in three of 18 endometrial carcinomas. These different intermediate filament expression patterns of müllerian duct-type carcinomas, only partly related to the morphologic appearance of the specific type of tumor, might reflect the multipotentiality of differentiation of müllerian duct-derived epithelia. Cytoskeletal features of potential diagnostic value, especially in metastatic carcinomas, are discussed.

Adenocarcinoma↗
PubMed1991

[The frequency of false aneurysms of the femoral artery following heart catheterization and PTA (percutaneous transluminal angioplasty)].

In a prospective study, the arterial puncture site was studied sonographically in 1120 patients who had undergone cardiac catheterisation or angioplasty (renal or extremities). Contrary to the figures in the literature, there was an incidence of 3.84% of false aneurysms (catheters 5.26%, angioplasty 2.36%). Conventional sonography and colour-coded duplex sonography were of equal value for demonstrating false aneurysms, but colour-coded duplex sonography was superior for demonstrating their relationships and haemodynamic effects.

Adult↗
PubMed1991

[Color-coded duplex sonography of the extracranial arteries supplying the brain: diagnostic significance and sources of error in comparison with i.a. DSA].

The findings of color Doppler flow imaging of the extracranial cerebral arteries in 75 patients were compared with i.a. DSA. Carotid stenoses greater than 50% and carotid occlusions were shown by sonography with a sensitivity of 91% and a specificity of 97%. The severity of the stenosis was in agreement in 88% of cases using the two methods. Sonography of the vertebral arteries achieved a sensitivity of only 65% and a specificity of 88%. Sonographic examination of the ophthalmic artery in order to demonstrate carotid stenosis achieved a sensitivity of only 29% and provided no additional information. Retrobulbar kinking of the ophthalmic artery was found in 30/178 vessels and may be a cause of misinterpretation.

Angiography, Digital Subtraction↗