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Biomedical subjects

M Osborn

Publications and source records attributed to M Osborn.

At least 163 records · Page 9Linked to original sources
PubMed1984

Small cell neuroendocrine (oat cell) carcinoma of the male breast. Immunocytochemical and ultrastructural investigations.

A case of small cell neuroendocrine (oat cell) carcinoma of the breast in a 52-year old male is presented. Oat cell carcinomas have been reported in various extrapulmonary sites, but this is the second case of a primary oat cell carcinoma of the breast and the first one to have been documented in a male. The tumor was investigated histologically, immunocytochemically and ultrastructurally. The relationship to so-called "carcinoid" mammary tumors is discussed.

Breast↗
PubMed1984

Distinction of nephroblastomas from other childhood tumors using antibodies to intermediate filaments.

Ten nephroblastomas were investigated by antibodies to intermediate filaments. In seven cases, which in light microscopy were characterized by the presence of blastema and tubules, immunofluorescence microscopy with IF-specific antibodies reveals expression of cytokeratin and vimentin in blastema cells, while tubules were only labelled by the cytokeratin antibodies. This result was independent of whether the conventional cytokeratin antibody or monoclonal antibodies specific for cytokeratin 18 were used. Stroma cells were vimentin-positive. In two cases nephroblastomas were undifferentiated and also lacked tubuli formation. In both these tumors blastema cells were vimentin-positive and cytokeratin-negative. Finally one case of clear cell sarcoma of the kidney could only be labelled by the vimentin antibody. Thus antibodies to intermediate filaments seem to be useful tools to distinguish nephroblastomas from neuroblastomas or rhabdomyosarcomas, especially in cases of metastasis.

Child↗
PubMed1984

Actin paracrystal induction by forskolin and by db-cAMP in CHO cells.

Forskolin, a hypotensive diterpine, is assumed to be a potent activator of adenylate cyclase leading to increased levels of cAMP. When this drug is used at 10(-5) M on CHO-C14 cells in culture, it induces within 15 min actin paracrystals in all cells. At this time the paracrystals are mostly situated close to the cell periphery. Electron microscopy (EM) shows structures typical of actin paracrystals. Scanning electron microscopy (SEM) reveals a reduction in surface microvilli and blebs. Identical results can be obtained by adding 1 mM db-cAMP to the culture medium directly. The paracrystals are observed within 15 min and thus represent one of the earliest ultrastructural changes so far described for reverse transformation of CHO cells by db-cAMP. The microtubular and vimentin profiles appear unchanged by forskolin treatment of CHO-K1 cells. Out of currently unknown reasons forskolin does not induce the actin transformation in several other commonly used cell lines.

Actins↗
PubMed1984

A monoclonal antibody against nuclear lamina proteins reveals cell type-specificity in Xenopus laevis.

Immunofluorescence microscopy shows that the monoclonal murine antibody PKB8 stains the nuclear lamina of various somatic cells from vertebrates as diverse as mammals, birds and amphibia. It also decorates the nuclear periphery of oocytes from rat and chicken but does not react with spermatocytes, spermatids and spermatozoa. Immunoblotting experiments demonstrate reaction with lamina polypeptides A, B and C of rat, with lamina polypeptide A of chicken, and with lamina polypeptides LI and LII of erythrocytes of the frog, Xenopus laevis. Antibody PKB8 does, however, not bind, on blotted polypeptides and on sections through ovaries, to the pore complex-lamina polypeptide of Mr 68000 present in Xenopus oocytes. These results reveal the existence of a common antigenic determinant in all three lamina polypeptides of mammals, in one lamina polypeptide of chicken and in two amphibian lamina polypeptides. The immunological data also indicate that, in Xenopus laevis, pore complex-lamina polypeptides of somatic cells and oocytes are distinct. The Mr 68000 protein of Xenopus oocytes is also different from polypeptides LI and LII of somatic Xenopus cells by tryptic peptide mapping. The results suggest that nuclear pore complex-lamina polypeptides represent a family of related polypeptides containing regions highly conserved during evolution and that these polypeptides can be differentially expressed in cells of at least one species, Xenopus laevis.

Animals↗
PubMed1984

The clarification and assessment of a method of psychotherapy.

The 'conversational model' of psychotherapy was investigated with a view to discovering which behaviours distinguish psychotherapists trained in this method from others, of equal clinical experience. A rating scheme designed to capture the theoretical aspects of the model, and 30 predictions were made concerning behaviours which were expected to distinguish the psychotherapists. Five psychotherapists were matched to five psychiatrists who had not been trained in this method; each doctor took on four patients for therapy, and each patient was seen on five occasions. All interviews were recorded, and excerpts from the recordings rated. Only ten of the 30 predictions were upheld. In ten further predictions, the psychotherapists displayed the appropriate behaviours, but the behaviours were not peculiar to the model, since eclectic psychiatrists also displayed them. Six model behaviours were not practised frequently by the psychotherapists, and four 'non-model' behaviours were equally common in either group. The research formed the basis for the preparation of materials to teach psychotherapeutic skills in a more efficient way.

Behavior↗
PubMed1984

Immunohistochemical distinction of human carcinomas by cytokeratin typing with monoclonal antibodies.

Carcinomas of different origin have been tested in immunofluorescence microscopy with the monoclonal murine antibodies CK1-CK4, which recognize a single cytokeratin polypeptide (human cytokeratin No. 18) present in simple but not in stratified squamous epithelia, and with the monoclonal antibody KG8.13 and guinea pig kerA antibodies, both of which recognize a variety of cytokeratins common to almost all epithelial cell types. Tumors derived from simple epithelia, including adenocarcinomas and some other tumors such as ductal breast carcinomas, were strongly stained by all three antibodies. So was a transitional carcinoma of the bladder. In contrast, basal cell epithelioma, cloacogenic carcinoma, and squamous cell carcinoma of skin, tongue, and esophagus appeared negative with CK1-CK4 but positive with the other two antibodies. Other squamous cell carcinomas derived from epiglottis and cervix uteri showed a mixture of positive and negative cells when tested with CK1-CK4, although all tumor cells were positive when tested with KG8.13 and with kerA. Thus, use of an appropriate collection of cytokeratin antibodies with different specificities not only allows tumors of epithelial origin to be distinguished from other tumor types but, in addition, allows a further subdivision of carcinomas in relation to their histologic origin.

Adenocarcinoma↗
PubMed1984

Antibodies to different intermediate filaments as histogenetic tumormarkers.

Fifty primary carcinomas, nineteen nonmuscular sarcomas, ten rhabdomyosarcomas, one malignant ependymoblastoma and seventeen sympathetic derived tumors have been studied to determine what type of intermediate filaments they express, using affinity purified antibodies to prekeratin, vimentin, desmin, glial fibrillary acidic protein (GFA) and to the different neurofilament proteins. The tissue was ethanol fixed and paraffin embedded before use. In all carcinoma cases the tumor cells are stained by antibodies to prekeratin, whereas tumor cells in nonmuscular sarcomas could only be labeled by antibodies to vimentin. In the cases of rhabdomyosarcomas tumor cells are clearly decorated by antibodies to desmin. The one case of malignant ependymoblastoma was positive when tested with antibodies directed against glial fibrillary acidic protein (GFA). While most of the sympathetic derived tumors react positively with sera directed against the different neurofilament proteins, three neuroblastomas did not react with sera against any of the known intermediate filament types. Wider use of such sera would seem particularly useful in cases such as neuroblastomas, undifferentiated carcinomas, lymphomas and rhabdomyosarcomas.

Antibodies, Neoplasm↗
PubMed1984

[Differential diagnosis of tumors of the head and neck using immunohistologic and electron optic studies].

With indirect immunofluorescence microscopy it is possible to visualize intermediate-sized filaments which show a cell-specific distribution and in this manner establish a light-microscopical diagnosis in certain cases which are difficult or impossible to differentiate using conventional methods. We applied the same method to tumours of the head and neck region. Intermediate-sized filaments were studied in four malignant lymphomas, seven carcinomas and four metastases of carcinomas. Malignant lymphomas showed a positive reaction with antibodies to vimentin, carcinomas a positive reaction with antibodies to keratin. Using a monoclonal antibody against a single keratin polypeptide (cytokeratin 18) a further subdivision of the carcinomas was possible. The keratinizing squamous cell carcinoma and two non-keratinizing squamous cell carcinomas showed a positive reaction with the conventional antibody against keratin, but a negative reaction with the monoclonal antibody against cytokeratin 18. One adenocarcinoma, two anaplastic carcinomas and one lymphoepithelial carcinoma were positive with the conventional antibody against keratin and with the monoclonal antibody against cytokeratin 18. Thus lymphoepithelial carcinomas and anaplastic carcinomas should probably not be regarded as special variants of squamous cell carcinoma. In all metastases the same intermediate-sized filaments were demonstrable as in the primary tumour. Certain advantages of immunofluorescence microscopy when compared to diagnostic electron microscopy are discussed.

Adenocarcinoma↗
PubMed1984

Depression at the menopause.

For the doctor confronted with an unhappy menopausal woman, who is weepy, irritable, and sleeping badly, it is often difficult to decide whether these symptoms are a natural consequence of her endocrine status or due to social or psychological factors. Certainly, a link between depression and the menopause should not necessarily be assumed.

Cultural Characteristics↗
PubMed1984

Monoclonal antibodies specific for vimentin.

Previously described vimentin monoclonal antibodies recognize other cellular or intermediate filament proteins in addition to vimentin. In contrast the set of murine monoclonal antibodies described here and elicited using porcine vimentin as antigen appear specific for vimentin. All seven antibodies react only with vimentin in "immunoblot" analysis on gel electrophoretically separated polypeptides from total cell extracts. They do not recognize other closely related intermediate filament proteins including desmin and GFA (glial fibrillary acidic protein). Immunofluorescence microscopy on tissue sections shows a positive reaction in connective tissue, endothelial cells, vascular smooth muscle cells and astrocytes. Typical intermediate filament profiles are documented in fibroblasts and in other cultured cells known to contain vimentin. Although all antibodies react with human and porcine vimentin some show species-specific restriction when rat, mouse and chicken vimentin are used. These results, together with different IgG types and certain aspects of the staining patterns, allow a subdivision of the antibodies. The vimentin antibodies described here complete a set of monoclonal antibodies each specific for only one intermediate filament protein type. Their reaction on human material allows their use in pathology to determine the histogenetic origin of neoplasms.

Animals↗
PubMed1983

Monoclonal antibodies to desmin, the muscle-specific intermediate filament protein.

A set of monoclonal antibodies to desmin has been isolated from a fusion of mouse myeloma cells with spleen cells from mice immunized with purified porcine desmin. Eleven group I antibodies recognized desmin in the immune blot, and using defined desmin fragments the epitope has been tentatively assigned as lying between residues 325 and 372. When cell lines were tested in immunofluorescence only the human line RD and hamster BHK-21 were positive. When tissue sections were used, skeletal, cardiac, visceral and some vascular smooth muscle cells were positive. Thus, the group I antibodies appear specific for desmin and do not recognize other intermediate filament proteins. Group II monoclonals recognized not only desmin in the immune blot but also other polypeptides. The epitope of this class is located between residues 70 and 280. In immunofluorescence on cell lines and tissues, the staining patterns of group II antibodies were more complicated and demonstrate that not only other intermediate filament proteins but also additional antigenic determinants are being recognized. The group I antibodies stain, as expected from their desmin specificity, rat and human rhabdomyosarcomas and thus appear to be useful reagents in pathology.

Animals↗
PubMed1983

Malignant melanomas contain only the vimentin type of intermediate filaments.

Six malignant melanomas have been examined for the type of intermediate filament they contain. All six cases showed positive staining of intermediate filaments with antibodies to vimentin, with cells containing large numbers of melanosomes being stained less strongly in general. The tumor cells did not react with antibodies to keratin, desmin, neurofilaments or glial fibrillary acidic protein. Thus typing of intermediate filaments can distinguish melanoma from undifferentiated carcinoma, but not from lymphoma or sarcoma. Since melanocytes are known to be vimentin positive, and since most of the samples we studied were from metastases, these results are a further indication that the intermediate filament type typical of the parental cell is retained in the metastases, as well as in the primaries of solid tumours. The implications of vimentin positivity for the histiogenesis of the melanocyte are also discussed.

Cytoskeleton↗
PubMed1983

Vimentin filaments in peritoneal macrophages at various stages of differentiation and with altered function.

Comparative immunofluorescence microscopic, transmission and scanning electron microscopic investigations were carried out to study the arrangement and significance of vimentin filaments in monocytes, macrophages, epithelioid cell equivalents and multinucleate giant cells under various different functional conditions, and in the presence of functional disorders. Uncoated or sebum-coated coverslips were implanted in the peritoneal cavity of Wistar rats. Some of the animals received repeated i.p. injections of colchicine. Rats were killed at various times 1 to 14 days after initiation of the experiment. The number of macrophages, the degree of their activation, and the growth of cells on the coverslips was considerably greater on sebum-coated than on uncoated implants. Various characteristic vimentin distribution patterns were found dependent on the cell cycle, the form and volume of the cell, and on the degree of differentiation and maturity; they were also related to the type and intensity of cell function. These patterns were best developed in ordered multinucleate giant cells. Repeated administrations of colchicine resulted in a marked flattening of the cell body on the coverslips--which correlated with a considerable reduction in the number of vimentin filaments and of cytoplasmic processes--and also in the formation of circumscribed erect, tree-like protuberances. The "trunk" of these structures comprised closely bundled vimentin filaments, and the cell nucleus was located at its base. These morphologic changes, which were associated with a functional insufficiency, proved to be reversible.

Animals↗