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Biomedical subjects

A C Markey

Publications and source records attributed to A C Markey.

33 records · Page 2Linked to original sources
PubMed1990

Activation and inducer subset phenotype of the lymphocytic infiltrate around epidermally derived tumors.

An in situ analysis of the mononuclear cell infiltrate found in association with a range of benign, premalignant, and malignant epidermal tumors is described. The predominant cell phenotype was that of the recently described immunoregulatory helper/inducer T lymphocyte. A large number of lymphocytes expressed antigens associated with cellular activation, suggesting an ongoing immunologic response by the host against the tumor, although evidence of in situ proliferation of these cells was lacking. These findings suggest that the infiltrate found in association with cutaneous tumors does not represent passive accumulation of lymphocytes from the circulation but rather an active antitumor response.

Antibodies, Monoclonal↗
PubMed1990

Platelet activating factor-induced clinical and histopathologic responses in atopic skin and their modification by the platelet activating factor antagonist BN52063.

The clinical and histopathologic responses to intradermal platelet-activating factor (PAF-acether) in atopic subjects, without evidence of atopic dermatitis are documented. An immediate acute wheal and flare reaction was observed in all volunteers. Histopathologically, the reaction was characterized by a predominantly neutrophilic response, which was seen at 30 minutes and was maximal at 4 hours. Eosinophils were observed in the infiltrate as early as 30 minutes after injection, and were maximal by 12 hours. The specific PAF-acether antagonist BN52063 antagonized the acute flare response to intradermal PAF-acether but had little effect on cellular recruitment at the site of injection.

Adult↗
PubMed1990

T-cell inducer populations in cutaneous inflammation: a predominance of T helper-inducer lymphocytes (THi) in the infiltrate of inflammatory dermatoses.

The mononuclear infiltrate found in a variety of inflammatory dermatoses was characterized by a predominance of T helper-inducer lymphocytes (THi), CD4+/CD45RA-/CD45RO+, a population of cells responsible for maintaining and promoting immune reactions. Only small numbers of T-suppressor-inducer lymphocytes (TSi), CD4+/CD45RA+/CD45RO-, cells responsible for inducing CD8 suppressor-effector cells to 'down regulate' immune reactions, were seen. The predominance of CD4+ THi lymphocytes was common to all dermatoses studied and suggests a common final pathway in chronic cutaneous inflammation, irrespective of initial causative factors.

CD4-Positive T-Lymphocytes↗
PubMed1990

Altered expression of major histocompatibility complex (MHC) antigens by epidermal tumours.

Alteration in the major histocompatibility complex (MHC) antigen expression by cutaneous tumours may enable them to escape host defence mechanisms and to invade surrounding tissue. Immunohistochemical studies in a wide range of epidermally derived tumours demonstrated expression by keratinocytes of the class II molecule HLA-DR in squamous cell carcinoma (SCC) (2 of 8 cases) and keratoacanthoma (KA) (2 of 7 cases). Additionally, HLA-DP and DQ were expressed by single cases of SCC and KA, although, unlike the widespread distribution of DR, DP and DQ, were only present on keratinocytes adjacent to the inflammatory infiltrate. Therefore, keratinocytes in cutaneous tumours, like carcinoma cells of the colon and breast, may express class II MHC antigens during tumour growth. Beta-2-microglobulin (B2M), an invariant MHC class I marker, was absent in all cases of basal cell carcinoma. Variable loss of B2M was observed in squamous cell carcinoma, Bowen's disease and actinic keratoses, suggesting reduced B2M expression by dysplastic cells. However, the variability in B2M staining both between and within diagnostic categories restricts it's immunodiagnostic usefulness.

Antigens, Neoplasm↗
PubMed1989

Keratinocyte expression of OKM5 antigen in inflammatory cutaneous disease.

Keratinocyte expression of the monocyte/macrophage surface antigens defined by OKM1 and OKM5 antibodies (Ortho Diagnostics) was examined using the peroxidase anti-peroxidase immunohistochemical technique. A range of inflammatory cutaneous disorders were investigated, including lichen planus, psoriasis and atopic dermatitis. Positive suprabasal keratinocyte expression of OKM5 antigen was observed in all disorders, while keratinocyte staining with OKMI antibody was consistently negative. These results provide further evidence that keratinocytes may play an important role in cutaneous immune responses. Furthermore, they are consistent with the recent observation that HLA-DR positive keratinocytes may modulate cutaneous immunological reactions by inducing T-cell unresponsiveness.

Adult↗
PubMed1989

Human cutaneous mast cells--a study of fixative and staining reactions in normal skin.

Routinely used formal saline fixation reduces the number of demonstrable mast cells in human skin by up to 30% compared with paired specimens fixed in Carnoys medium. Using metachromatic (toluidene blue), orthochromatic (alcian blue/safranin), enzymatic (chloroacetate esterase reaction) and immunofluorescence (berberine and fluorescein conjugated avidin) staining techniques, mast cells were demonstrated and quantified. Alcian blue/safranin and fluorescein-conjugated avidin were both superior to the other staining methods used. We recommend the use of Carnoys medium fixed tissue stained with either alcian blue/safranin or conjugated avidin for optimal visualization and assessment of mast cells in human skin.

Acetates↗
PubMed1989

Identification of CD16/NKH-1+ natural killer cells and their relevance to cutaneous tumour immunity.

The presence of natural killer (NK) cells, as defined by reactivity with the monoclonal antibodies Leu 7, Leu 11 and Leu 19 was assessed in the inflammatory infiltrate around epidermal neoplasms and compared with findings in a range of inflammatory dermatoses. HNK-1+ (Leu 7) cells were present in a wide range of malignant, pre-malignant and inflammatory disorders. Cells positive for the more specific NK cell antigens CD16 (Leu 11)/NKH-1 (Leu 19) had a distribution mainly restricted to cases of squamous cell carcinoma (five of nine) and keratacanthoma (three of seven). The variability in distribution between the different antibodies suggests that the majority of cutaneous HNK-1+ cells are not NK cells, but represent cross-reacting T lymphocytes. The qualitatively distinct distribution of CD16+ and NKH-1+ cells around some cases of squamous cell carcinoma and keratoacanthoma is of interest but their absence from a number of such cases calls into question a specific effector role for natural killer cells in these squamoproliferative tumours.

Antigens, Differentiation↗