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K Röser

Publications and source records attributed to K Röser.

At least 19 recordsLinked to original sources
PubMed2005

[Immunohistochemical characterization of salivary gland tumors with tissue micro-arrays].

Systematic analysis of gene expression in salivary gland tumors is necessary to identify genes associated with specific tumor types. From the salivary gland register of the University Hospital Hamburg-Eppendorf sufficient samples of various tumors were available to generate Tissue Micro-Arrays (TMA). In light of the considerable heterogeneity of salivary gland tumors, this study was aimed at evaluating the suitability of TMA in salivary gland diagnostics and research. Epithelial antigens are not sufficient for a tumor-type-specific characterization. Myoepithelial markers are suitable for distinguishing biphasic tumor types from purely epithelial tumors. The detection of amylase in acinic cell carcinomas, and the detection of steroid hormone receptors in these and other malignant salivary gland tumors particularly in combination with the expression of transcription factors, oncogenes and proliferation associated antigens result in characteristic expression profiles. These may prove to be valuable for further investigations, especially on the molecular level.

Biomarkers, Tumor↗
PubMed2005

[Significance of molecular-cytogenetic findings in mucoepidermoid carcinoma as an example of salivary gland tumors].

Chromosome translocations in tumors frequently give rise to fusion genes encoding proteins with oncogenic activities. Mucoepidermoid carcinomas (MEC) are characterized by a t(11;19)(q21-22;p13) translocation found in approximately 60% of the tumors. This t(11;19) translocation results in a fusion gene consisting of exon 1 of the MECT 1 gene and exons 2-5 of the MAML 2 gene. As a result of the t(11;19) a fusion protein is generated which, independent of NOTCH-ligands, activates the transcription of the NOTCH target gene HES 1. The altered function of MAML 2 causes a disruption of NOTCH signalling which suggests a novel mechanism of tumorigenesis. Pending the elucidation of the t(11;19) at the molecular level of an apparently identical chromosomal translocation in Warthin's tumor, the identification of the translocation in MEC by FISH- and/or RT-PCR-analyses may become important in diagnosis and might have prognostic relevance. Warthin's tumors are benign salivary gland neoplasms with a distinctive histomorphology and histogenesis completely different from MEC.

Carcinoma, Mucoepidermoid↗
PubMed2003

Translocations t(11;18)(q21;q21) and t(14;18)(q32;q21) are the main chromosomal abnormalities involving MLT/MALT1 in MALT lymphomas.

The recently discovered MLT/MALT1 gene is fused with the API2 gene in the t(11;18)(q21;q21), which characterizes about one-third of MALT lymphomas. In order to screen for variant translocations and amplifications of MLT/MALT1, we have developed a novel, undirected two-color interphase fluorescence in situ hybridization (FISH) assay with two PAC clones flanking MLT/MALT1. This assay was applied to 108 marginal zone B-cell lymphomas (MZBCLs), including 72 extranodal MALT lymphomas, 17 nodal, and 19 splenic MZBCL. In 19 MALT lymphomas (26%), but in none of the nodal or splenic MZBCL, separated hybridization signals of the MLT/MALT1 flanking probes, were found. Further FISH analyses showed that 12 of these 19 cases displayed the classical t(11;18) and the remaining seven cases revealed the novel t(14;18)(q32;q21), involving the MLT/MALT1 and IGH genes. The frequency at which these translocations occurred varied significantly with the primary location of disease. The t(11;18) was mainly detected in gastrointestinal MALT lymphomas, whereas the t(14;18) occurred in MALT lymphomas of the parotid gland and the conjunctiva. Amplification of MLT/MALT1 was not observed in any of the lymphomas analyzed. We conclude that the translocations t(11;18)(q21;q21) and t(14;18)(q21;q32) represent the main structural aberrations involving MLT/MALT1 in MALT lymphomas, whereas true amplifications of MLT/MALT1 occur rarely in MZBCL.

Breast Neoplasms↗
PubMed2002

[Involvement of the maxillary sinus in Langerhans cell histiocytosis].

AIM: A clinical presentation of Langerhans cell histiocytosis (LCH) in the maxillary sinus of two patients is given. LCH in the maxillary sinus is a rare occurrence. Our aim was to compare the different treatment alternatives available and to suggest a classification as well as a therapeutic regime. PATIENTS AND METHOD: Records and clinical data of two patients treated between 1994 and 2001 were retrospectively evaluated. Both patients suffered from LCH in the maxillary sinus and the maxilla regions. Only surgical treatment was used. After resection, a large defect of the maxillary sinus, which did not allowing coverage, was seen in both cases. After reconstructive operations, closure was finally achieved. Both patients underwent follow-ups, whereby one suffered from a relapse after 15 months. RESULTS: Although one of the patients under investigation showed a recurrence of LCH, we are of the opinion that surgical treatment is very effective in the elimination of this condition. A proposal for a classification of LCH in the oral-maxillo-facial-region is made. CONCLUSIONS: The evaluation of our clinical study suggests that LCH is a disease that should be treated surgically. Only in very severe cases should the surgical treatment be complimented by either radiotherapy or chemotherapy. In disseminated cases, especially chemotherapy seems to improve the outcome. Surgery offers the possibility of eliminating systemic side effects.

Dental Implantation, Endosseous↗
PubMed2002

[Experimental and histomorphologic studies of healing processes of anastomoses of the carotid artery in the Wistar rat animal model with immunohistochemical imaging of collagen IV].

INTRODUCTION: The main risk in free flap tissue transfer is posed by the microvascular anastomosis. The dangers confronting the anastomosis are thrombosis, aneurysm, and vascular insufficiency. Collagen IV is associated with the basement membrane complex. It plays an essential role in vascular tissue organization and supports mechanical properties of vessels. We used a long-term animal experiment to gain a new understanding of histomorphological apposition of anastomosis and distribution of collagen IV. METHODS: Seventy Wistar rats, seven groups of ten animals each, were operated. A 4-mm long segment of the common carotid artery was isolated and reinserted. After a varying length of time (between directly after the operation and 6 months later), the common carotid arteries including bifurcation were isolated after cardiovascular perfusion. Carotid arteries were embedded, and cross-sections were stained with hematoxylin and eosin, Verhoeff's tissue elastin stain, and immunohistochemical anti-collagen IV antibody. By using the above-described technique in each section four anastomoses were examined. The histomorphology and intensity of the anti-collagen IV stainings were evaluated. RESULTS: Compression, shift, and dehiscence as forms of vessel apposition were often seen. We observed an overexpression of collagen IV in the media in cases of compression and shift. The grade of expression of collagen IV in the anastomosis depends on the extent of the injury. CONCLUSIONS: A well-performed microvascular anastomosis is clinically important not only for the acute phase after the operation, but also for the long-term course. The application of antibodies to identify the collagen IV distribution is valuable for studying vascular healing. Further applications could be used in follow-up studies of vascular prostheses.

Anastomosis, Surgical↗
PubMed2001

[About the prognostic value of Her-2 gene-amplification and cell-proliferation in salivary duct carcinoma of the major salivary glands - a pilot-study].

INTRODUCTION: The salivary duct carcinoma (sdc) represents a rare variant of the group of adeno-carcinomas of the salivary glands. Histopathologically, it is marked by solid and cribriform cell nests with central necrosis, displaying distinct similarity with the ductal carcinoma of the breast, where prognosis can be correlated with Her-2 gene-amplification. Based on this histopathological similarity, the prognostic value of Her-2 gene amplification in SDC was examined in the presented pilot-study. PATIENTS AND METHODS: Four own patients with different clinical courses were examined in regard to their histopathological features, Her-2 gene-amplification and proliferation (Ki67). RESULTS: Three of the four patients died tumor related 2.4, 5.5 and 8.2 years after initial diagnosis. The remaining patient died tumor-free 6 year after diagnosis (myocardial infarct). The two patients with an early recurrent disease and distant metastasis showed a high Her-2 expression and proliferation (Ki67), compared to the other two patients. CONCLUSION: In the presented pilot-study a distinct correlation between Her2-gene-amplification, proliferation (Ki67) and clinical course could be observed. Additional analysis to evaluate this aspect seems rectified, especially under recognition of therapy decisions.

Adenocarcinoma↗
PubMed2001

Angiogenesis, vascular endothelial growth factor and platelet-derived growth factor-BB expression, iron deposition, and oxidation-specific epitopes in stented human coronary arteries.

Pathogenesis of in-stent restenosis remains poorly understood because information from human histopathologic studies is scarce. We used an improved saw-grinding and cutting method on methacrylate-embedded samples containing metal stents, which allows in situ hybridization and immunohistochemical analysis of in-stent restenosis. Twenty-one samples were collected 3 hours to 3 years after stenting from 6 patients aged 36 to 81 years. Except in very early samples collected within hours after the stent deployment, neovascularization was present in all segments studied. At advanced stages, extensive neovascularization was located mainly at the luminal side of the stent struts and was only rarely accompanied by inflammatory cells. The neovessels colocalized with vascular endothelial growth factor (VEGF)-A mRNA and protein expression as well as with iron deposits and oxidation-specific epitopes, which imply the presence of chronic oxidative stress. VEGF-A expression was detected in the same areas containing macrophages, endothelial cells, and, to a lesser extent, smooth muscle cells, which also showed platelet-derived growth factor-BB expression. We conclude that in-stent restenosis features neovascularization, VEGF-A and platelet-derived growth factor-BB expression, and iron deposition, which is most probably derived from microhemorrhages. These mechanisms may play an important role in the development of neointimal thickening and could provide useful targets for the prevention and treatment of in-stent restenosis.

Adult↗
PubMed2000

A new approach to demonstrate cellular activity in bone formation adjacent to implants.

Bone tissue repeatedly formed in titanium 6-aluminum 4-vanadium rabbit bone harvest implants was collected in vivo at various times between 12 days and 5 weeks. Qualitative and quantitative examinations on undecalcified thin sections were performed in the light microscope. The amount of bone tissue was calculated on routinely stained sections. Alkaline (ALP) and acid phosphatase (ACP) enzyme activities were investigated. We also performed immunohistological detection of bone matrix proteins. Increasing bone density as well as an increasing mineralization of the tissue was observed in the biopsies with increasing time. The ALP and ACP activities were similar at short times (12 days and 2 weeks). With increasing time the ALP activity was stronger than that of ACP. The results from the immunohistochemical detection of osteonectin, osteopontin, bone sialoprotein, and collagen I and II demonstrated changes in the tissue differentiation with time. The tissue formation in the canal became more mature with time of ingrowth, as observed with the various techniques used in this study. Owing to these methodical developments, undecalcified ground sections may be used for detailed analysis of various phases of tissue formation in close proximity to implants.

Acid Phosphatase↗
PubMed1999

Bone-tissue formation and integration of titanium implants: an evaluation with newly developed enzyme and immunohistochemical techniques.

BACKGROUND: Examination of the tissue surrounding retrieved implants involve routine investigations on cut and ground sections. Undecalcified sections with implants in situ are histologically stained followed by qualitative and quantitative observations of the tissue response to the implants by light microscopy. PURPOSE: A novel technique that allows for the accurate definition and quantification of enzymes involved in bone formation (alkaline phosphatase) and resorption (acid phosphatase) in the tissue is presented. MATERIALS AND METHODS: Commercially pure titanium and titanium alloy (Ti6Al4V) implants were retrieved after 6 and 12 weeks of healing in rabbit bone. In addition, 4-week specimens from commercially pure titanium bone harvest chambers placed in rabbit bone were used. Undecalcified cut and ground sections were produced and evaluated with enzyme and immunohistochemical staining techniques. RESULTS: The titanium implants retrieved after 6 weeks of insertion in rabbit bone revealed a higher activity of both alkaline phosphatase and acid phosphatase activity compared to the implants followed for 12 months. The former samples revealed ongoing bone-tissue remodeling in the interface, whereas the latter ones showed steady-state bone conditions. Applying the new technique allowed for investigation of various bone proteins present in the tissue that had formed inside titanium canals of harvest chambers at various times of follow-up. CONCLUSIONS: The combination of routine histologic stainings with enzyme and immunohistochemical technique of cut and ground specimens is a valuable tool in the investigations of retrieved implants from humans and animals. This novel technique now may be used to describe the state of bone regeneration in the interface zone associated with implant research.

Acid Phosphatase↗
PubMed1997

The spectrum of giant cells in tumours of the salivary glands: an analysis of 11 cases.

In view of the different terminology for salivary gland tumours with giant cells, eleven cases were analysed by histopathology and immunocytochemistry. Four cases (three pleomorphic adenomas, one carcinosarcoma in a pleomorphic adenoma) were classified as having a foreign-body giant cell reaction, and five cases (two mucoepidermoid carcinomas, one acinic cell carcinoma, two carcinomas in pleomorphic adenomas) as having a sarcomatoid osteoclast-like giant cell reaction. In two further cases a giant cell tumour and a giant cell granuloma were associated with carcinomas in pleomorphic adenomas. All giant cells showed characteristic expression of CD68 as a typical marker for histiocytes and macrophages with their origin in mononuclear haematopoetic stem cells. There was no evidence for an epithelial origin of the giant cells because all those examined had a negative reaction to cytokeratin. Foreign-body cells were characterized by cytoplasmic vacuoles and irregularly dispersed nuclei. They showed a focally circumscribed reaction mostly outside the connective tissue pseudocapsule of the tumours. The sarcomatoid osteoclast-like giant cell reactions in carcinomas were distinctly intermingled with the carcinomatous patterns. In contrast, the associated osteoclast-like giant cell tumour was distinctly separate from the salivary gland tumour tissue and was composed of numerous larger osteoclast-like giant cells with a greater number of nuclei (more than 20); these giant cells were uniformly distributed throughout the tumour tissue. The giant cell granuloma was also separate from the carcinoma and was composed of nests of smaller, more irregularly distributed giant cells.

Adenoma, Pleomorphic↗
PubMed1995

Composition and posttranslational modification of individual collagen chains from osteosarcomas and osteofibrous dysplasias.

The composition of collagen was analyzed and the degree of lysyl hydroxylation of individual collagen chains was determined in four osteosarcomas and two osteofibrous dysplasias. In addition, the tumor proliferation (number of mitoses, proliferating-nuclear-antigen-positive cells, MIB) as well as the response to chemotherapy (morphological regression grade) were checked. All tumors contained a high proportion of collagen III and, in all but one osteosarcoma, pepsin-extracted collagens I and III were overmodified. Furthermore, the proportion of diglycosides in collagen I was about four times higher than in controls. The collagen composition and modification resembled those of bones at early stages of human development. One osteosarcoma and both osteofibrous dysplasias were in the normal range of lysyl hydroxylation. There was no correlation between the collagen properties and the histopathological marker of tumor proliferation.

Adolescent↗
PubMed1993

Selenium deficiency and fulvic acid supplementation induces fibrosis of cartilage and disturbs subchondral ossification in knee joints of mice: an animal model study of Kashin-Beck disease.

Kashin-Beck disease is an acquired, chronic and degenerative osteoarticular disorder. Selenium deficiency and fulvic acid in drinking water have been implicated in the cause of this disease. Pathologically, chondronecrosis of the growth plate and articular cartilage and subconsequent disturbance of ossification were observed in the joints. In this animal model study, mice were fed with a selenium deficient diet and fulvic acid supplemented drinking water for two generations. In undecalcified histological preparations of bone we carried out histological staining to detect mineralized and unmineralized bone and cartilage. The results revealed that selenium deficiency and fulvic acid supplementation induced degeneration of the articular cartilage in the knee joints of mice. Dynamic fluorescent labelling of ossification, enzyme histochemical detection of alkaline phosphatase activity in osteoblasts and a typical immunohistochemical localization of collagens type I and II indicated the development of fibrocartilage at the articular surface of knee joints, resembling the early stages of osteoarthrosis. This became obvious by disturbed development of the articular space and meniscus, markedly impaired formation of subchondral bone and early differentiation failure during enchondral ossification. This animal model provides an approach to study the molecular pathogenesis of Kashin-Beck disease.

Animals↗
PubMed1992

Enzyme and immunohistochemistry on undecalcified bone and bone marrow biopsies after embedding in plastic: a new embedding method for routine application.

A simplified method of low temperature methyl and butyl methacrylate embedding (up -20 degrees to -15 degrees C) is demonstrated using a proper redox system of benzoyl peroxide and aromatic amine. This method combines the morphological superiority of plastic-embedded bone tissue and bone marrow sections with the advantages of specific enzyme histochemical and immunochemical markers. The method permits good preservation of morphological details, the survival of antigenic determinants and the retention of enzyme activities. The specimens were fixed in 1.6% formaldehyde and 5% sucrose in 0.02 M phosphate buffer at pH 7.4, washed in 0.02 M phosphate buffer and 5% sucrose, dehydrated with acetone and impregnated with monomers of embedding medium. All these steps were carried out at +4 degrees C. The method presented is especially suitable for enzyme histological and immunohistological diagnosis of primary and secondary bone tumours, soft tissue tumours, as well as myelo- and lymphoproliferative disorders of bone marrow biopsies. Examples are demonstrated with mono- and polyclonal antibodies and reaction products of hydrolytic enzymes.

Biopsy↗
PubMed1991

Subclones of C6 rat glioma cells differing in intermediate filament protein expression.

The C6 rat glioma cell line is shown to consist of a mixed population of cells which either contain vimentin (80% of the cells) or completely lack any cytoplasmic intermediate filament (IF) proteins. Subclones could be established with both phenotypes, indicating that these IF protein expression patterns represent stable phenotypic markers. Absence of IF proteins in C6 subclones could consistently be correlated with an altered cell morphology and a pronounced increase in the number of actin stress fibers. In vitro translation and hybridization assays suggest the absence of vimentin to result from a block at the transcriptional level. The data indicate that subcloning of the C6 cell line on the basis of IF protein expression seems to be a reasonable approach for obtaining homogeneous C6 cell populations which may represent suitable experimental models for studies on vimentin expression and glioma cell differentiation.

Animals↗
PubMed1989

Expression of nuclear lamins in mammalian somatic cells lacking cytoplasmic intermediate filament proteins.

Using immunofluorescence and immunoblotting techniques, we have examined the composition of the nuclear lamina in murine plasmacytoma cells, MPC-11, exposed to the phorbol ester TPA as well as in two cell lines devoid of cytoplasmic intermediate filament proteins, the human adrenal cortex carcinoma-derived cells SW-13 and the clone C6-M-D4 derived from the rat glial cell line C6. Our results show that the inhibition of proliferation and the induction of vimentin synthesis observed in TPA-treated MPC-11 populations are not paralleled by changes in the lamin complement of these cells, which contain lamin B but lack lamins A and C. Furthermore, the analysis performed on SW-13 and C6-M-D4 cell lines clearly demonstrates that mammalian somatic cells display considerable variations in lamin expression and indicates that lamin B may be the only lamin species constitutively expressed in mammalian cells.

Adrenal Cortex Neoplasms↗