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Biomedical subjects

G Rowden

Publications and source records attributed to G Rowden.

At least 91 records · Page 5Linked to original sources
PubMed1977

[The influence of humoral immune mechanisms on metastasizing tumors in humans (author's transl)].

Long-continued stimulation of the immune system by chronic infections or tumors leads to dysfunction of the immunoregulation. Different types of antibody, anti-antibody and immunocomplex point to the fact that it is not a matter of the weakening of the patient's immune defense but that these antibodies are important regulating mechanisms for the immune system. While antibodies directed against a tumor have a useful function for the patient with dissemination of metastasizing tumors, the anti-antibodies and antigenotypic antibodies represent a counterregulation which, in the advanced stage of the disease, eliminates the initial control.

Antibodies, Anti-Idiotypic↗
PubMed1977

Immuno-electron microscopic studies of surface receptors and antigens of human Langerhans cells.

A heteroantiserum, prepared in rabbits against fractionated cell membranes of a human B-lymphoblastoid cell line, was used to study the distribution of Ia antigen(s) in human epidermis. Indirect immunofluorescence staining demonstrated specific reactivity of dendritic supra-basal cells, consistent in location with Langerhans cells. Basally located cells were noted in biopsy specimens from vitiliginous skin and from the leukodermatous regions of halo naevi. The specificity of the reaction was confirmed at the ultrastructural level by means of ferritin labelling methods. Cell surface staining was confined in the epidermis to Langerhans cells. Fc and C3' receptors were studied by means of rosetting methods. Negative results were obtained on frozen sections, while 2-3% of cells formed rosettes when applied to an epidermal cell suspension.

Antigens↗
PubMed1976

Fetal antigens on the surface of human lymphoid cells.

Human B-lymphoblastoid cells established in long-term culture from healthy adults carry surface components that are normally found in human fetal tissues at about 10 wk of age. These antigens are strongly expressed on neoplastic B lymphocytes but not on thymocytes or a cultured T-cell line. They are carried by a small subpopulation of normal adult peripheral blood lymphocytes as well.

Antigens↗
PubMed1976

Distribution of adenosine triphosphatase in infiltrating ductal carcinoma and non-neoplastic breast.

The histochemical reaction for adenosine triphosphatase (ATPase) has previously been used to differentiate myoepithelial from epithelial cells in the breast and to investigate the possible contribution of myoepithelial cells to mammary carcinoma. Discrepancies in published reports prompted this study of ATPase in non-neoplastic breast and infiltrating ductal carcinoma. ATPase was localized mainly on myoepithelial cells of normal breast and was identified with significant frequency on epithelial cells in hyperplastic ducts. Infiltrating ductal carcinomas usually displayed a variable reactivity. In one instance, malignant cells demonstrating mucin production were found to be ATPase-positive. An infiltrating ductal carcinoma of the papillary type with apocrine features was also strongly ATPase-reactive. It is concluded that ATPase is not an exclusive marker of myoepithelial cells and, therefore, data resulting from the use of this enzyme to study the role of the myoepithelium in mammary carcinoma must be interpreted with caution.

Adenosine Triphosphatases↗
PubMed1976

Cellular localization of immunoglobulin within human maglignant melanomata.

The presence of antibody in patients with malignant melanoma is well established if one examines the serum. In this report we have attempted to identify antibody within solid tumours showing that they are rarely present in any appreciable quantity on the surface of tumour cells but can be seen frequently on a number of different types of host cell within the tumours. This is discussed in the light of the role of antibody in the circulation and the possibility of antibody behaving as a blocking factor in vivo.

Antibodies, Neoplasm↗
PubMed1976

Immune complexes in human melanoma: a consequence of deranged immune regulation.

Circulating immune complexes were detected in 62 individuals with malignant melanoma by precipitation with isolated human C1q and polyclonal rheumatoid factors. In 56 patients the C1q deviation assay showed low to moderate levels of complexes, with increased amounts with advancing stage of disease. Both heavy (greater than 19S) and intermediate (7S to 19S) varieties were present, and complexes containing tumor antigen-antibody or antibody-anti-antibody were identified. Complexes were found in the kidneys of one patient with malignancy and the nephrotic syndrome and in two further patients with melanoma in whom there were no clinical manifestations of nephrosis. Serial determinations in 51 patients showed slow cyclic variations in the levels of complexes and fluctuations in response to therapy. The coexistence of anti-antibodies, immune complex disease, and anergy in melanoma patients may indicate a deranged immune regulation consequent to chronic antigenic stimulation by the tumor.

Adult↗
PubMed1976

Fetal antigens in nonneoplastic conditions.

During studies that showed the presence of fetal antigens on the surface of human malignant melanoma tumor cells, polyvalent antisera specific for human fetal tissues of varying ages were developed. These reagents demonstrated varying patterns of expression of fetal antigens at different ages in various tissues of the human fetus. The possibility that nonneoplastic adult cells showing either maturation arrest or excessive proliferation also might express fetal antigens led to studies of human bone marrow. Although normal bone marrow cells expressed low levels of fetal antigens, large amounts were seen on bone marrow cells of patients with anemias due to iron, B12, or folic acid deficiencies, as well as on those with leukemia. Moreover, normal adult tissues adapted to long-term culture also expressed fetal antigens. After 3 weeks in organ culture adult human skin showed morphological changes similar to those seen in fetal periderm and strongly expressed fetal antigens. In addition, lymphoblasts in long-term cultured human lymphoid cell lines established from normal donors also carried surface fetal antigens. These latter antigens were shared with neoplastic B-cells (chronic lymphocytic leukemia) but not with T-cells. Their expression varied with the cell cycle. The reexpression of fetal antigens on malignant cells is thought to signal a basic derangement in the control of differentiation which is considered to be peculiar to neoplasia. However, these studies indicate that normal adult cells also may reexpress fetal antigens under circumstances unrelated to neoplasia but associated with either maturation arrest or rapid and excessive proliferation.

Adult↗
PubMed1975

Foetal-associated material: its expression in long-term cultured human skin.

Using immunofluorescence and electron microscopy, we have demonstrated the presence of "foetal substances" (antigens) in skin kept in tissue culture medium for periods of time ranging from 9 days-18 weeks. This is a specific reaction demonstrated with an anti-human foetal serum raised in New Zealand white rabbits. It is suggested that the expression of foetal substances by cells in the skin under these abnormal conditions might lead to the masking or modification of the normal histo-compatible antigens, enabling such skins to survive transplantation without rejection.

Adult↗
PubMed1975

Multilamellar cytosomes in a particular form of late-infantile amaurotic idiocy.

There is a particular form of late-infantile amaurotic idiocy in which no clear chemical-pathological or unique enzyme abnormalities have been identified to date. A distinctive morphological feature has been recognized on electron microscopical examination of tissues from these patients, which has been descriptively labeled with various terms, including "multilamellar cytosomes" (MLC). Illustrations of MLC in a patient with this late-infantile form of cerebroretinal degeneration show their reactivity with the periodic acid-silver methenamine reaction for glycoproteins. The MLC are shown to be morphologically identical in cerebral tissue obtained at biopsy, in the same tissue obtained three years later at autopsy, and in skeletal muscle.

Brain↗
PubMed1975

Long-term organ culture of human skin: an ultrastructural and immunochemical study.

Human skin grown in tissue culture medium for periods of up to 18 wk undergoes characteristic morphological changes. After an initial period of degeneration, new foci of epidermal cells arise at the dermo-epidermal junction and by rapid proliferation these cells spread out to form a complete second epidermal layer beneath the degenerating original strata. Stratification occurs in this new epidermis with incomplete keratinisation. The individual keratinocytes show ultrastructural similarities with fetal cells. There is a loss of complexity of the cytoplasm typified by a marked reduction in the numbers of keratin filaments and a decrease in the numbers of desmosomal contact areas. In addition, the formation of cilia and accumulation of glycogen in the cell cytoplasm are characteristic. The cytoplasm of the basal cells contains numerous polyribosomes and there is evidence of synthetic activity as illustrated by the proliferation of rough-surfaced endoplasmic reticulum and Golgi complex. Fluorescent and EM immunocytochemical staining with an anti-fetal antiserum demonstrates the development of fetal substances on the surface of cells during the regeneration stage occurring in the cultured skins. The significance of these observations concerning transplantability of cultured tissues is discussed.

Cell Division↗
PubMed1975

Ultrastructural studies of keratinized epithelia of the mouse. III. Determination of the volumes of nuclei and cytoplasm of cells in murine epidermis.

Simple morphometric analyses were applied to mouse epidermal specimens prepared for electrom microscopy. Mean values were obtained for the dimensions of cells and nuclei in basal, suprabasal, and granular layers. These measurements were applied to simplified models representing the shapes of cells in the three strata. A fourfold increase in cytoplasmic volume was observed as cells passed from the basal to granular layers. During this transition, the nuclear volume did not decrease significantly.

Animals↗
PubMed1975

Ultrastructural studies of keratinized epithelia of the mouse. IV. Quantitative studies of lysosomes.

Electron microscope cytochemical and simple morphometric studies have permitted an estimate to be made of the absolute numbers of lysosomes present in various cell layers of murine epidermis. Most lysosomes appear to be present in basal layer keratinocytes with few being detected in Langerhans cells or in granular layer keratinocytes. The observation that lysosomes are not numerous in any of the strata is discussed with respect to an alternative explanation for the presence of diffuse acid hydrolase activity in the granular layers.

Acid Phosphatase↗