PubMed Health⌕ Search

Biomedical subjects

R L Edelson

Publications and source records attributed to R L Edelson.

At least 91 records · Page 5Linked to original sources
PubMed1986

Tumor-associated antigen is expressed on lymphocytes from patients with acquired immunodeficiency syndrome.

Monoclonal antibody BE2 recognizes an antigen found on malignant T4+ lymphocytes from cutaneous T-cell lymphoma patients (CTCL). Normal peripheral blood lymphocytes do not express detectable levels of BE2 antigen. Forty-eight percent of patients with the acquired immunodeficiency syndrome (AIDS) had lymphocyte populations that were reactive with monoclonal antibody BE2. Peripheral blood lymphocytes from healthy homosexuals, patients with classical Kaposi's sarcoma or viral syndromes, and healthy normal controls were BE2-. Double-labeling studies demonstrated that BE2+ cells were T lymphocytes. This observation demonstrates that some AIDS patients as well as CTCL patients have circulating cells that express a common lymphocyte abnormality.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Quantification of methoxsalen-DNA adducts with specific antibodies.

Methods are now available for the quantification of carcinogen-DNA adducts in human tissues and can be used to screen populations for exposure to environmental carcinogens. One approach utilizes highly specific antibodies in sensitive immunoassays for quantifying adduct levels in DNA from various tissues. We have recently developed a panel of monoclonal antibodies that specifically recognize DNA modified by methoxsalen and ultraviolet A light (320-400 nm) (UVA). These antibodies have been characterized as to sensitivity and specificity by an enzyme-linked immunosorbent assay (ELISA). In a competitive ELISA, 50% inhibition of antibody binding occurred with 17 fmol methoxsalen-DNA photo adducts. There was also some antibody cross-reactivity with DNA modified by 4'-aminomethyl-4,5,8-trimethylpsoralen and 4',5-dimethylangelicin but not with free methoxsalen. A more sensitive ELISA has also been developed using fluorescence detection of enzyme activity. With this assay, one adduct per 10(8) bases can now be detected reliably. Adduct levels have been quantified in myeloma cells and lymphocytes treated in vitro with methoxsalen and UVA. In addition, in preliminary studies, adducts have been measured in lymphocytes isolated from patients undergoing extracorporeal photophoresis for cutaneous T-cell lymphoma. Quantification of methoxsalen adducts in patients should provide a basis for estimating risk resulting from psoralen plus UVA (PUVA) treatment.

Antibodies, Monoclonal↗
PubMed1985

Monoclonal antibodies to DNA modified by 8-methoxypsoralen and ultraviolet A light.

A panel of monoclonal antibodies have been developed which specifically recognize DNA modified by 8-methoxypsoralen (8-MOP) and ultraviolet A light (320-400 nm) (UVA). These antibodies have been characterized as to sensitivity and specificity by an enzyme linked immunosorbent assay (ELISA). In a competitive ELISA with the most sensitive antibody, 50% inhibition of antibody binding occurred at 17 fmole 8-MOP-DNA photo adducts. One adduct per 10(7) bases could be reliably detected. There was also some antibody cross-reactivity with DNAs modified by 4' aminomethyl-4, 5, 8-trimethylpsoralen and 4', 5-dimethylangelicin as well as DNA isolated from cells treated with 8-MOP and UVA. The primary specificity of one of the antibodies was shown to be the 4', 5' thymine monoadduct by competitive inhibition studies using HPLC fractions of an enzymatic digest of 8-MOP poly(dA-dT) . poly(dA-dT). These antibodies should allow the quantitation of adduct levels in various in vitro systems as well as humans exposed clinically to 8-MOP and UVA.

Animals↗
PubMed1985

Pathogenesis of cutaneous T-cell lymphoma.

Cutaneous T-cell lymphoma is a malignant disease whose behavior reflects its T-cell lineage. The biologic characteristics of the disease are understandable when viewed from a perspective of normal T-cell-skin interactions. Thus, it is of no surprise that this malignancy of helper T lymphocytes usually demonstrates a remarkable affinity for the skin at the outset and that, coincident with decreased dependence upon this unique environment, the extent and aggressiveness of disease increases. Although the inciting event responsible for the development of cutaneous T-cell lymphoma is unknown, a mechanism for local growth and distant expansion of malignant cells has been postulated in terms of IL-2-dependent and -independent growth phases. As our vision into the cellular and subcellular workings of this malignancy becomes more acute, specific therapeutic and preventive measures will emerge.

Cell Differentiation↗
PubMed1984

Internalization and acidification of insulin by activated human lymphocytes.

The binding and internalization of fluorescein isothiocyanate-conjugated insulin by nonactivated and phytohemagglutinin-activated circulating human lymphocytes was measured by flow cytometry. In confirmation of previous results, negligible binding or internalization was observed for unstimulated cells, while activated lymphocytes showed significant insulin binding. The majority of this insulin was demonstrated to be internalized via receptor-mediated endocytosis and acidified within 60 min after addition of insulin. Dual-fluorescence flow cytometry, using antibodies specific for human T cell subsets, was used to show that the expression of insulin binding sites occurs for at least some cells from both the helper/inducer and cytotoxic/suppressor T cell subsets. Insulin internalization is not an artifact of in vitro stimulation, since more than 90% of the unstimulated lymphocytes from a patient with a helper T cell leukemia are positive for insulin internalization. The usefulness of flow cytometric analysis for measuring lymphocyte activation in unstimulated populations and the therapeutic potential of the reported findings for control of lymphocyte proliferation are discussed.

Flow Cytometry↗
PubMed1984

Monoclonal antibody 4F2 reactive with basal layer keratinocytes: studies in the normal and a hyperproliferative state.

To establish a method for separating different keratinocyte subpopulations in the epidermis, we studied the specificity of monoclonal antibody 4F2 for keratinocytes. Preliminary screening experiments had previously demonstrated 4F2 reactivity with the epidermis. 4F2 reacted with a subpopulation (19.29 +/- 5.23%) of human epidermal cells in suspension. The membrane antigen identified by 4F2 continues to be expressed by cultured keratinocytes. In frozen tissue section using an indirect immunofluorescence technique, the 4F2-positive cells in the basal layer are sharply demarcated from the negative suprabasilar layers. Even in the hyperproliferative state of psoriasis, the 4F2 reactivity is confined to the basal layer. Cell suspensions of psoriatic epidermis demonstrated a greater percentage of reactivity with 4F2 (49.51% +/- 6.50%), probably reflecting the expanded population of basal layer cells. Monoclonal 4F2, therefore, reacts with a membrane antigen present on basal keratinocytes, and provides a probe for use in the isolation of the basal keratinocyte subpopulation. Thus, this antibody should be useful in studies of normal and aberrant differentiation of the epidermis.

Antibodies, Monoclonal↗
PubMed1984

Characterization of immature T cell subpopulations in neonatal blood.

A series of monoclonal antibodies directed against T cell differentiation antigens was used to identify circulating T cells in normal human neonates. Twenty-five cord blood samples, taken after cesarean or vaginal delivery, and 16 venous blood samples from normal adult controls were examined using monoclonal antibodies in an indirect immunofluorescence technique. The percentage of circulating OKT3 positive (pan-T cell) cells was significantly lower in the neonatal blood (52.8%) compared with the adult controls (74.9%) (P less than .001). Of the cord mononuclear cells, 58% showed reactivity with OKT10 (common thymocyte antigen) compared with only 7% in adult controls (P less than .001). The helper:suppressor T cell ratio was lower in cord blood (1:2) as compared with 1:3 for adult blood (P less than .005) as observed in these studies. These figures reflect the presence of a significant population (25%) of immature T cells in cord blood that expresses simultaneously both helper (OKT4) and suppressor (OKT8) phenotypes. Twenty-four percent of the T cells in cord blood also expressed OKT6 antigen (cortical thymocyte), a feature not found in adult blood. Double-labeling studies characterized a previously undescribed blood T cell phenotype, which was simultaneously OKT6 and OKT3 (pan-T cell) positive; of the cells reactive with OKT3, 43% also were positive with OKT6. This study reveals the presence of immature populations of T cells in normal human neonatal blood exhibiting phenotypes characteristic of normal developing thymocytes and a previously undescribed cell phenotype.

Adult↗
PubMed1984

Effect of monochromatic UVA light and 8-methoxypsoralen on human lymphocyte response to mitogen.

The ultraviolet-A (UVA) action spectrum for inhibition of DNA synthesis by lymphocytes stimulated with phytohemagglutinin and sensitized with 8-methoxypsoralen (8-MOP) (100 ng/ml) was determined by exposing cells to 0.33 and 1.0 J/cm2 of sub-bands of UVA light at 322, 334, 346, 358 and 370 nm. For lymphocytes irradiated with 0.33 J/cm2, the wavelength for optimal inhibition of DNA synthesis was 334 nm (P less than 0.001). Relatively high doses of monochromatic UVA light (6J/cm2) significantly inhibited lymphocyte proliferation at all wavelengths tested: 64% at 370 nm, 90% at 358 nm, 78% at 346 nm and greater than 99% at both 334 and 322 nm (P less than 0.001 at each wavelength). The optimal wavelength for selective 8-MOP enhanced inhibition of DNA synthesis by lymphocytes in the 334-346 nm range is shown to support the usual assumption that crosslinks represent a lethal cellular event.

DNA↗
PubMed1983

The diagnostic use of monoclonal antibodies in a variety of dermatologic conditions.

Monoclonal antibodies have been used to characterize subpopulations of lymphocytes in a variety of dermatologic conditions by immunofluorescence and immunoperoxidase staining. Various clinical presentations of cutaneous T-cell lymphoma have been shown to be neoplastic expansions of helper T-lymphocytes. Immunoperoxidase studies using subset-specific monoclonal antibodies have allowed the differentiation of patients with cutaneous T-cell lymphoma from lymphocytoma cutis and B-cell lymphomas secondarily involving the epidermis. Increased numbers of OKT-6 positive Langerhans' cells in the dermal infiltrates of patients with cutaneous T-cell lymphoma may be another immunocytological marker of this disease. Studies done on circulating lymphocytes of patients with psoriasis and pemphigus vulgaris have shown normal ratios of T-cell subsets in patients with psoriasis and an expansion of the helper T-cell subset in an untreated patient with pemphigus. Immunofluorescence and immunoperoxidase techniques used in conjunction with highly specific monoclonal antibodies have been shown to be valuable for histopathologic study of dermatologic diseases.

Antibodies, Monoclonal↗
PubMed1983

Thymopoietin-like substance in human skin.

A heterologous antithymopoietin (anti-TP) antibody was used to determine whether a TP-like molecule is present in the epidermis, since such factors have been postulated to play a part in known T cell-epidermal cell interaction. Examination of cytocentrifuge smears of freshly separated human epidermal cells stained by indirect immunofluorescence revealed that 8-14% of these cells possessed cytoplasmic reactivity with the anti-TP antibody. Similarly, 2-5% of human epidermal cells, maintained in tissue culture for 2-8 weeks, showed cytoplasmic staining with the anti-TP antibody. Double-labeling immunofluorescence studies, with the anti-TP antibody and a monoclonal antibody specifically reactive with Langerhans cells (OKT6), demonstrated that cells possessing this TP-like substance were not Langerhans cells. In situ studies of 4-microns frozen sections of normal human skin indicated that the cell population which possesses the TP-like substance is the basal layer of keratincoytes in the epidermis.

Fluorescent Antibody Technique↗