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Biomedical subjects

T Löning

Publications and source records attributed to T Löning.

At least 145 records · Page 8Linked to original sources
PubMed1985

Quantitative analysis of immunocompetent cells in human normal oral and uterine cervical mucosa, oral papillomas and leukoplakias.

Using monoclonal antibodies reacting with T-cell subpopulations, Langerhans cells and macrophages, the number and distribution of cells of the immune system in normal oral and cervical mucosa was determined and statistically compared with that in oral papillomas and oral leukoplakias. Increased numbers of labelled cells were found in oral leukoplakias and particularly in oral papillomas. In the epithelium of all specimens, Langerhans cells and T-lymphocytes of the suppressor/cytotoxic phenotype as well as of the helper phenotype were seen. Suppressor/cytotoxic and helper T-lymphocytes were in equal numbers in the epithelium of oral papillomas, but were about 2:1 in all other lesions. In normal oral epithelium, macrophages were rare but were in greater numbers in leukoplakias and papillomas. In the connective tissue of all lesions, more labelled cells were present than in epithelium with T-lymphocytes predominant. Although Langerhans cells were rare in connective tissue, many were seen in oral papillomas.

Antibodies, Monoclonal↗
PubMed1985

Analysis of oral papillomas, leukoplakias, and invasive carcinomas for human papillomavirus type related DNA.

Five papillomas, five leukoplakias, and six carcinomas were investigated for the presence of papillomavirus group-specific antigens and viral DNA. Viral proteins were identified with genus-specific papillomavirus antibodies. Cloned human papillomavirus (HPV) 11 and 16 DNA were used as probes in Southern blot hybridization at conditions of different stringency in order to determine viral DNA. Four of five papillomas, four of five leukoplakias, and three of six carcinomas reacted with HPV DNA probes and revealed some stained cells after exposure to HPV antibodies. HPV type 16 was found in one carcinoma and HPV type 11 was demonstrated in another case of carcinoma.

Adult↗
PubMed1984

Occurrence of papillomavirus structural antigens in oral papillomas and leukoplakias.

Six oral papillomas and 7 oral leukoplakias were studied with genus-specific antibodies against detergent-disrupted papillomaviruses. Indirect immunofluorescence staining was applied to frozen sections. Distinct nuclear staining of superficial keratinocytes was seen in 5 of 6 oral papillomas, 2 of 5 homogenous leukoplakias, and in 2 cases of nodular leukoplakia, one of these showing transition into an invasive carcinoma. Papillomavirus antibodies offer a new way to detect and localize papillomaviruses in epithelial hyperplasias. The relevance of the immunomorphological identification of papillomavirus-associated antigens is discussed with special reference to the molecular hybridization technique.

Adult↗
PubMed1984

Morphologic study of jejunal mucosal transplants for the replacement of oral mucosa.

Biopsies were taken at 8 and 12 weeks and at 6 months from oral jejunal mucosal transplants in 5 patients who had undergone extensive surgery for tumors of the floor of the mouth. Microvascular anastomosed jejunal mucosa had been used for the primary reconstruction. Histological findings included flattening of the jejunal relief, atrophy and erosion of the epithelium with reduction of jejunal excretion and marginal overlapping of oral mucosa. Immunohistochemical labelling of the cytoskeleton revealed that jejunal epithelium does not undergo rapid metaplasia in the course of adaptation to oral mucosa. These findings indicate that the jejunal mucosa does not completely change its architecture and does not adapt to the requirements of the oral cavity after a period of 6 months.

Adult↗
PubMed1984

[Immunopathology of the oral mucosa. Oral immune system--inflammatory reactions--tumor-"marker"--virus identification].

The present study was concerned with oral reparative and inflammatory reactions, benign epithelial proliferations and malignant lesions including their prestages. Following investigations of normal oral mucosa, biopsy and surgical specimens of diseased human oral mucosa were studied with light and electron microscopical methods. In addition, experimental models of oral wound healing and carcinogenesis were developed. Combining morphological (immunofluorescence, immunocytochemistry, electron microscopy) and biochemical (SDS polyacrylamide gel electrophoresis) techniques differentiation and function of epithelial and non-epithelial cells of the oral mucosa were investigated. Clinical pathology. 725 oral lesions were collected from the files of the Dermatological Clinic of the University of Hamburg. Among these lesions epithelial hyperplasias and neoplasias represented the most frequent alterations of the oral mucosa. The incidence of premalignant lesions (3.7%) was consistent with the percentages reported in the literature. On frozen or glutaraldehyde-fixed tissue samples the value of immunohistological and ultrastructural methods was examined with particular respect to the distinction of reactive inflammatory processes from true premalignant and malignant lesions and with special reference to the differential diagnosis of epithelial and non-epithelial tumours. Examples were given for immunological characterization of inflammatory lesions and for histogenetical typing of neoplasias. Normal oral mucosa. Biochemical and morphological investigations of keratin filaments showed that basal and suprabasal epithelia contain different keratin polypeptides related to the degree of cell differentiation. These cytoskeletal modifications were seen to be associated with cell membrane differentiations which was demonstrated by different lectin affinities to basal and suprabasal compartments of epithelium. At the epithelial-mesenchymal interfaces macromolecular substances appeared (e.g. fibronectin) which are produced by basal epithelia (e.g. laminin) and connective tissue cells leading to the formation of the basement membrane zone. Immune competent cells were seen to be regular components of normal oral mucosa. Within the epithelium Langerhans cells and T lymphocytes of the suppressor/cytotoxic phenotype were shown to be the predominant inflammatory cells. B lymphocytes, T lymphocytes of the suppressor/cytotoxic and helper/inducer phenotypes and typical macrophages represented cellular elements of the connective tissue. All these non-epithelial cells were found to contain vimentin filaments.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

Predominant cutaneous infiltration by OKT6- and OKT8-positive cells in a case of Sézary syndrome.

Using an immunoperoxidase (skin biopsy) and an immunofluorescence (peripheral blood, bone marrow punctate) technique, and monoclonal antibodies raised against peripheral mature lymphocytes, T helper subsets, T suppressor subsets, and Langerhans cells, we found a predominant dermal infiltration with lymphocytes of the suppressor phenotype and a predominant epidermal infiltration with Langerhans cells in a patient with Sézary syndrome (cutaneous T-cell lymphoma, CTCL). Repeated peripheral blood examinations showed an increased percentage of lymphocytes of the helper phenotype. A bone marrow examination revealed a ratio of suppressor/helper subsets of 1:4. The findings in the skin seem to be inconsistent with most of the results of previous studies in patients with CTCL; the significance of these findings is discussed.

Aged↗
PubMed1983

Wound repair of the oral mucosa. Immunohistological and 3H-thymidine-autoradiographic observations.

The migratory and proliferative capacity of oral epithelium was studied after induction of subepithelial suction blisters in palatal rat mucosa. FITC-coupled lectins and their affinities to epithelial cells at the wound margin were analyzed by immunofluorescence microscopy. Immunocytochemical distribution of 67 K-keratin polypeptides in different epithelial layers were studied using specific antisera against keratin proteins. By means of 3H-thymidine-autoradiography the proliferation of epithelial basal cells and their migration at the wound edge was quantified by evaluation of the labelling index. Double labelling was performed, combining the autoradiographic and the keratin staining technique. It was found that the subepithelial suction blister showed rapid repair (epithelial regeneration after 3-4 days). Peanut Agglutinin (PNA) showed a selective affinity to the basal 2-3 layers of oral rat mucosa. No modifications of lectin affinities were found in epithelial wound repair. PNA-positive keratinocytes were demonstrated in the migratory epithelial tongue. The selective presence of 67 K-keratin (67 K) in the suprabasal epithelial cell layers was interpreted as an indication of the differentiation process in rat oral mucosa. The 3H-thymidine-labelling index of basal cells increased significantly, beginning at the wound edge after 24 h. The peak of the labelling index curve was located in the vicinity of the wound after 96 h. Double labelling technique revealed 67 K-negative and 3H-thymidine-positive basal cells as well as 67 K-positive and 3H-thymidine-negative cells at the migration front. These observations support findings that migrating epithelial cells in oral wound healing derive both from undifferentiated (str. basale) and from differentiated (inferior str. spinosum) cell compartments.

Animals↗
PubMed1983

A second look at intraepithelial Langerhans cells in mycosis fungoides and related disorders. Ultrastructural study with special reference to Langerhans granules and virus-like particles.

Skin biopsies of patients with small and large plaque parapsoriasis, premycotic lesions and mycosis fungoides in different stages were examined. Special attention was paid to the relationships between Langerhans cells (LC) and the neighbouring keratinocytes and lymphocytes. At the contact areas of LC and keratinocytes as well as LC and lymphocytes, particular cell membrane phenomena were observed. Aggregations of Langerhans granules and fusions of granules with LC plasma membranes were found exclusively at LC-keratinocyte interfaces. At LC-lymphocyte contact zones cell membrane appositions were seen. In all cases investigated, virus-like particles were mainly found in LC and indeterminate cells (IDC). In 3 cases lymphocytes also contained these particles. It was of particular interest that virus-like particles were observed in skin specimens of all diseases investigated. Discrimination of these particles from other cellular organelles - especially lysosomes - was difficult, however. The significance of our findings, particularly regarding to the supposed virus aetiology of cutaneous T cell lymphomas, is discussed.

Adult↗
PubMed1983

Identification of inflammatory cell phenotypes in human oral carcinomas by means of monoclonal antibodies.

Monoclonal antibodies reacting with human T cell sub-populations, Langerhans cells and macrophages were used to examine the quantitative distribution of immune-competent cells in normal oral mucosa and invasive oral carcinomas. Both immunofluorescent and immunoperoxidase procedures were applied. In normal oral epithelia, the dominant immune-reactive cell was the Langerhans cell, positive for OKT 6 and expressing HLA-DR gene products (OKIa1+). Many intra-epithelial non-epithelial cells (non-keratinocytes), belonged to the lymphocyte system carrying the suppressor/cytotoxic phenotype (OKT 8+). This lymphocyte sub-population was also the most prominent cell type in the normal mucosal stroma. The quantitative evaluation of immune-competent cells in squamous cell carcinomas revealed elevated numbers of all the inflammatory cell sub-populations investigated (suppressor/cytotoxic lymphocytes, helper/inducer lymphocytes, Langerhans cells, macrophages) compared with the normal oral mucosa. There was a striking increase in suppressor/cytotoxic lymphocytes (OKT 8+) and in cells of the macrophage system, including Langerhans cells (OKIa1+, OKM 1+, OKT 6+). In the stroma distant to the tumour complexes, many helper/inducer lymphocytes (OKT 4+) were also observed.

Antibodies, Monoclonal↗
PubMed1983

Keratin and tissue polypeptide antigen profiles of the cervical mucosa.

Epithelial cell differentiation is accompanied by biochemical and immunological changes of cytoplasmic components. Antibodies against filamentous and nonfilamentous substances of epithelial cells are helpful for the visualization of the gradual maturation processes in different epithelia. The present study is concerned with differentiation characteristics of the normal cervical mucosa and, in particular, the squamocolumnar junction. Antibodies against tissue polypeptide antigen (TPA), large keratins (67K), and all keratin fractions were applied in this investigation. Antibody binding was revealed by indirect immunofluorescence. TPA was found to be characteristic for basal layer cells and undifferentiated reserve cells of the transformation zone. In contrast, 67K represent an indication of squamous differentiation and were only found in suprabasal cells of the ectocervical epithelium and in keratinizing cells of the transformation zone. Antibodies against all keratin fractions were seen to label all epithelial cells. The immunomorphological definition of epithelial compartments of the normal cervical mucosa supports earlier concepts of the physiological processes at the squamocolumnar junction and represents an interesting tool for studies of cervical neoplasias of various differentiations.

Adult↗
PubMed1982

Thymolipoma in association with myasthenia gravis.

Among 72 thymic tumors that were examined we have found five (7.5%) thymolipomas. Two of these patients have had clinical symptoms. One, a five-year-old boy, has had an erythrocyte hypoplasia as well as a hypogammaglobulinemia. The other patient, a 56-year-old man, has had myasthenia gravis. This case is the second in the world literature in which a thymolipoma is associated with symptoms of myasthenia gravis. The clinical, radiologic, and histopathologic findings and the pathogenesis of thymolipoma are discussed.

Adult↗
PubMed1982

Identification of Langerhans cells: simultaneous use of sera to intermediate filaments, T6 and HLA-DR antigens on oral mucosa, human epidermis and their tumours.

Langerhans cells in oral mucosa and epidermis have been identified using antibodies to intermediate filament proteins in conjunction with antibodies to T6 and HLA-DR antigens. Langerhans cells, lymphocytes and melanocytes are positive when tested with antibodies to vimentin, and negative with antibodies to prekeratin. Langerhans cells are also positive with antibodies directed against HLA-DR and T6 antigens. In contrast keratinocytes are positive for prekeratin and negative for vimentin, HLA-DR and T6. These methods provide a useful tool for the identification of Langerhans cells at the level of the light microscope, and have been used to show changes in the number and arrangement of these cells in squamous cell carcinomas of skin and oral mucosa, and in inflammatory conditions.

Antibodies, Monoclonal↗
PubMed1982

Dyskeratosis in human and experimental oral precancer and cancer. An immunohistochemical and ultrastructural study in men, mice and rats.

Dyskeratotic cells were examined with light and electron microscopy in human oral leukoplakias and carcinomas and in chemically-induced oral premalignant and malignant lesions of mice and rats. Specific antisera against small and large keratins were used to analyse the distribution of keratin polypeptides. In normal oral mucosa, basal cells did not react with antibodies against large keratins in contrast to the suprabasal cells which did react. Small keratins were found in all epithelial cell layers. In human and experimental premalignant and malignant lesions, intensely labelled dyskeratotic cells were seen, which contained small and large keratins regardless of their position in the epithelium. At the ultrastructural level, these cells showed dense aggregates of tonofilaments. Dyskeratotic cells were often seen in advanced stages of degeneration of phagocytosis of these cells by macrophages and giant cells was frequent. The disturbance of the keratinization process in oral precancer and cancer is easily visualized using keratin antisera. Keratin analysis can give new insights in epithelial maturation and may be helpful for the classification of oral leukoplakia.

Animals↗