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Biomedical subjects

G Seifert

Publications and source records attributed to G Seifert.

At least 109 records · Page 6Linked to original sources
PubMed1987

[Invalid status in neurologic diseases].

Authors analysed causes of invalidity in neuropsychiatric diseases within a single district. The share of neurological complaints amounts to 24%. Multiple sclerosis and epilepsy are the most important classes of syndromes. The results was compared with data known by pertinent literature. Demands appearing relevant for expert valuation of that kind of diseases are referred.

Adult↗
PubMed1986

A monoclonal antibody that detects myoepithelial cells in exocrine glands, basal cells in other epithelia and basal and suprabasal cells in certain hyperplastic tissues.

Myoepithelial and luminal cells of human exocrine glands can be positively identified with two different monoclonal antibodies. Myoepithelial cells including those of the salivary gland, mammary gland and sweat gland are positively identified by an antibody CKB1. This antibody does not stain luminal cells, but stains the basal cell layer of certain human stratified epithelia and a few basal cells in simple epithelia. Thus myoepithelial cells and basal cells have certain common features. Luminal cells can be positively stained with the CK5 monoclonal keratin antibody specific for keratin polypeptide 18; this antibody does not stain myoepithelial cells. Of interest is that CKB1 also appears to stain basal and suprabasal cells in certain hyperplastic conditions.

Antibodies, Monoclonal↗
PubMed1986

Metastatic tumors to the parotid and submandibular glands--analysis and differential diagnosis of 108 cases.

The distinction between primary salivary gland tumors and metastases of other primary tumors in salivary glands is of special importance for therapy and prognosis. In the files of the Salivary Gland Register, 10,944 cases were collected during 1965 and 1985. Among these cases, there were 108 cases of metastatic tumors to the parotid and submandibular gland. The pathohistological analysis of these tumors revealed the following data: 47 cases (43%) of metastatic tumors were localized in the parenchyma of the parotid gland (37 cases) or of the submandibular gland (10 cases). 61 cases (57%) displayed metastases in the lymph nodes of the parotid gland (38 cases) or of the submandibular gland (23 cases). The sublingual gland was free of metastatic tumors. 65 metastatic tumors originated from primary tumors in the neighborhood (head and neck). 32 tumors were carcinomas of the skin, 17 tumors were melanomas, and 13 tumors were nasopharyngeal cancers. Metastases of thyroid cancers were found in 3 cases. The relative frequency of metastases in the lymph nodes of the salivary glands is due to the intense drainage with lymph vessels and the presence of many lymph nodes which are localized especially in the gland parenchyma or around the parotid gland. 21 metastatic tumors originated from primary tumors distant from the head and neck region. There were metastases of lung cancers (7 cases), renal cancers (6 cases), mammary cancers (6 cases), colonic cancer (1 case) and uterus cancer (1 case). Clear cell carcinomas in salivary gland tissue should always be checked for a metastasis of a primary renal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Adenoid cystic carcinoma of the salivary glands: an immunohistochemical study.

Twenty-four cases of adenoid cystic carcinoma from the Salivary Gland Registry of the University of Hamburg were analysed with respect to their differentiation and subclassification. With immunohistochemical methods, several groups of marker substances were analysed in these tumors: marker for a glandular function; immunoglobulins; metalloproteins; tumor markers; substances associated with the basal membrane and carbohydrate chains. The following patterns of histological differentiation were found: cribriform pattern with typical pseudocysts; tubular pattern with ductal elements; trabecular pattern with predominance of hyalinized stromal elements; basaloid pattern with low differentiated cells. For every pattern, a special immunohistochemical profile could be established. The morphological and immunohistochemical analysis revealed the following relation between the different patterns: Origin of the malignant proliferation is presumably the terminal ductal system of the salivary glands (indifferent cell of the reserve cell type). This cell can differentiate in 2 directions: a myoepithelial and a ductal cell type. Immunohistochemically, the presence of basement membrane-associated substances is accompanied by the appearance of myoepithelial-like cells. The presence of secretory products is a feature of ductal cells.

Antibodies, Neoplasm↗
PubMed1986

The occurrence of blood group substances (A, B, H, Le-a, Le-b) in salivary glands and salivary gland tumors. An immunohistochemical investigation.

The distribution of blood group substances A, B, H, Le-a and Le-b in normal and neoplastic salivary gland tissue was evaluated by means of immunohistochemistry. The serological ABH blood group status of one third of the patients was known. Lewis blood group and secretory status were not known. In normal tissue, expression of blood group antigens corresponded to the serological blood group. Blood group substance H was present in almost every gland, regardless of the serological blood group. In submandibular glands, Le-b was rather selective for mucous acini. In tumors, a relationship of blood group expression to a glandular pattern and a high differentiation could be observed. Blood group substances were expressed at a high level in benign and highly differentiated malignant tumors. In poorly differentiated malignant tumors, they were mostly absent. Blood group expression evaluation could be of value in establishing the level of functional differentiation in salivary gland tumors.

ABO Blood-Group System↗
PubMed1986

Epithelial salivary gland tumors in children and adolescents. Analysis of 80 cases (Salivary Gland Register 1965-1984).

In the Salivary Gland Register (University of Hamburg), 9883 cases were recorded from 1965 to 1984. Among these cases there were 3,326 neoplasms, of which 3,017 were epithelial in origin. In this latter group, 80 neoplasms arose in children and adolescents. Among these 80 persons, there was a slight predominance of females; 57 tumors (71%) were localized in the parotid gland, and only 6 (8%) in the submandibular gland. The incidence of the tumor types was different in children and adolescents as compared to the incidence in adults: monomorphic adenomas were virtually absent in children (only 1 patient), and benign tumors were also less common (65%). The incidence of mucoepidermoid tumors was remarkable (12 cases, 15%). Acinic cell tumors occurred more frequently (5 cases, 6%). The neoplasms have been analyzed histologically. Two very rare tumors, a monomorphic salivary duct adenoma and an embryonal carcinoma, were also studied by electron microscopy and immunohistochemistry.

Adenoma↗
PubMed1986

Immunohistochemical investigations on the epimyoepithelial islands in lymphoepithelial lesions. Use of monoclonal keratin antibodies.

The histogenetic origin of cells in the epimyoepithelial islands occurring in patients with Sjoegren's syndrome has been investigated by using different monoclonal antibodies. The majority of cells in these islands reacted with broad specificity antibodies against keratins. The same cells are stained by a monoclonal antibody CKB1 which detects myoepithelial (basket) cells and basal cells (around the ducts) in normal salivary gland tissue, but which does not stain ductal epithelial cells. Conversely, the cells are not stained by the antibody CK5 which stains ductal epithelial cells in normal salivary gland tissue. The relation of the epimyoepithelial islands to the myoepithelial/basal cell system is thus demonstrated. Certain implications for practical use in surgical pathology are discussed.

Aged↗
PubMed1986

[Mesenchymal (non-epithelial) salivary gland tumors. Analysis of 167 tumor cases of the salivary gland register].

The total material of the Salivary Gland Register (1965-1985) contained 167 mesenchymal tumours with an intra- or paraglandular localisation. This corresponds to 1.5% of all cases of the Salivary Gland Register or to 5% of all salivary gland tumours. Periglandular tumours without relation to the salivary gland tissue, metastatic tumours or malignant lymphomas were not considered in this study. With respect to the localisation, the age and sex distribution and the histopathological classification the following results were obtained: 90% of all mesenchymal tumours were localised in the parotid gland and 10% in the submandibular gland. In lipomas, the percentage of the parotid gland was even 95%; in lymphangiomas, however, it was only 80%. Angiomas occur preferably in the first and second decades and represent in this age period nearly 90% of all mesenchymal tumours. The age peak of lipomas lies in the fifth to sixth decades, whereas neurogenic tumours are distributed relatively equal over the fourth to seventh decades. A sex disposition was seen in lipomas (85% in males), neurinomas (65% in females) and neurofibromas (75% in males). 90% were benign mesenchymal tumours, 10% sarcomas. Within the benign tumours 47.5% were angiomas, 22.5% lipomas, 16% neurogenic tumours and 4% rare benign tumours. In angiomas (79 cases) haemangiomas (50 cases), lymphangiomas (17 cases), mixed haemangiomas and lymphangiomas (9 cases) and haemangiopericytomas (3 cases) could be seen, in neurogenic tumours (27 cases) neurinomas (12 cases), neurofibromas (12 cases) and neurofibromatoses (3 cases), in sarcomas (17 cases) malignant fibrous histiocytomas (5 cases), malignant schwannomas (5 cases), embryonal rhabdomyosarcomas (4 cases) and other rare sarcomas (one case each myxoid liposarcoma, leiomyosarcoma, malignant haemangioendothelioma).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemangioma↗
PubMed1985

Sonographic tissue characterisation in thyroid gland diagnosis. A correlation between sonography and histology.

Punch biopsy was carried out in 32 cases in which thyroid gland changes were sonographically classified as being of homogeneously normal or of homogeneously low echogenicity. Mean follicle lumen size was morphometrically determined from the histological sections. This produced a significant, positive correlation between echogenicity and follicle size. The mean follicle lumen diameter in so-called echonormal structures was 67 microns (SD +/- 23 microns), and 25 microns (SD +/- 8 microns) in low-echogenic lesions. Thus normal echogenicity represented a normofollicular or macrofollicular structure, while a low echogenicity pattern indicated a microfollicular or solid tissue structure. The structure of thyroid carcinomas is not homogeneously normofollicular or macrofollicular; in exceptional cases they are such only focally. Therefore the significance of these findings lies in the exclusion of malignancy in the event of homogeneously normal echogenicity.

Adenoma↗
PubMed1985

Subcellular localization of tissue polypeptide antigen and cytokeratins in epithelial cells (salivary ad mammary glands). Combined use of the cryoultramicrotomy and the protein A-gold technique.

Epithelial cells from various sites and at various stages of differentiation reveal distinct cytokeratin polypeptide patterns. WE have localized these heterogeneous elements at the subcellular level in human salivary glands and in a solid tumor of the breast using a monoclonal and a polyclonal antibody against cytokeratin, and an antibody against tissue polypeptide antigen (TPA) which seems to be related to some cytokeratins. Labeling by the cytokeratin antibodies was more intense in squamous and duct cells than in acinar cells. The TPA:B1 antibody reacted predominantly with duct cells and to a lesser extent with acinar and squamous cells. A precise evaluation of the labeling pattern and a well-preserved cell structure appeared to be important factors in obtaining more detailed information about intermediate filament proteins. The cryoultramicrotomy and the protein A-gold technique are suitable for these studies.

Breast↗
PubMed1985

Overview of animal test methods for skin irritation.

Determining the irritant effects of chemicals in experimental animals provides the public with information on and protection against possible hazards that may arise from exposure of the human skin. Furthermore, the data obtained are used for registration and classification purposes. This paper reviews the methods proposed in the most important guidelines (OECD, EEC and FIFRA guidelines) and points out the critical experimental points. It shows that the introduction of OECD Guideline No. 404 can lead to a reduction in the number of test animals used for skin irritation testing.

Animals↗
PubMed1985

Cystadenolymphoma: an immunohistochemical study with special reference to Ig E and mastcells.

Cystadenolymphomas (adenolymphomas) were analysed by immunohistochemical studies for the presence of immunoglobulin A, E, G and M. The distribution pattern was examined by a quantitative analysis. The relative ratio of immunoglobulins was 31.8% (Ig A), 26.6% (Ig E), 28.6% (Ig G) and 13% (Ig M). The different compartments of the lymphoid stroma were analysed separately (subepithelial area, parafollicular area, follicular area). The distribution of mast cells was studied in a parallel approach by the toluidine blue technique. These cells were found in the stroma, but also in the epithelial parts. Our results show that the subepithelial zone in cystadenolymphomas is a region of special cellular reaction (plasma cells, mast cells). The Ig E producing plasma cells and the mastcells seem to play a special role in these tumors.

Adenolymphoma↗
PubMed1985

The importance of tumor markers in oral pathology. II. Cell membrane and cytoplasmic antigens as tumour markers.

Important tumour markers in tumours of the oral mucosa and salivary glands are intermediate filaments of cytoskeleton, oncofetal and proliferative antigens, lectin receptors and blood group substances, enzymes, metalloproteins and viral antigens. The special occurrence of the following tumour markers was demonstrated: keratin, vimentin, carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA), lectins (helix pomatia antigen = HPA, peanut agglutinin = PNA), Thomsen-Friedenreich-antigen, blood group substances A and B, amylase, lactoferrin, viral antigens of papilloma virus (group 11 and 16). In oral dysplasia and squamous cell carcinomas, relationships exist between the presence of keratin filaments and cell differentiation. Lectins represent membrane-orientated markers of differentiation. A loss of blood group substances A and B can be observed in oral dysplasias. Papilloma viruses and viral antibodies can be demonstrated in papillomas, leukoplakias and carcinomas. The salivary gland tumours show a distinct pattern of distribution for keratin, vimentin, CEA, TPA, metalloproteins and enzymes. Transplanted human salivary gland tumours in athymic nude mice keep the same tumour marker profile as in the primary tumor.

Antigens, Neoplasm↗
PubMed1985

Markers of oral and salivary gland tumors: immunocytochemical investigations.

In oral dysplasias and squamous cell carcinomas, relationships exist between the presence of keratin filaments and cell differentiation. The keratinized areas of high differentiated carcinomas are carcinoembryonic antigen (CEA) positive. The labeling of the higher molecular keratins is similar to the distribution of lectin receptors so that lectins represent membrane-oriented markers of differentiation. In dysplasias a gradual loss of blood group substances A and B can be observed. Squamous cell carcinomas possess no substances A or B. H antigen as precursor of A and B is increased in preneoplasias and absent in carcinomas. In oral papillomas, leukoplakias, and carcinomas virogen koilocytotic cell changes, papilloma viruses and viral antibodies can be demonstrated. In salivary gland tumors a distinct pattern of distribution for keratin, vimentin, CEA, tissue polypeptide antigen (TPA), metalloproteins, and enzymes can be observed. The cellular stromal reaction (lymphocytes, Langerhans cells, and so forth) can be defined more exactly by monoclonal antibodies.

Antigens, Viral↗