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Biomedical subjects

M A Everett

Publications and source records attributed to M A Everett.

At least 55 records · Page 3Linked to original sources
PubMed1981

In situ demonstration of OKT 6-positive cells in cutaneous lymphoid infiltrates.

A monoclonal antibody, OKT 6, has been developed against an antigen which is expressed by immature T cells as part of their normal intrathymic differentiation, but not by mature peripheral T cells. It was though that a search for the expression of such an antigen might be worthwhile in prelymphomatous conditions. This communication describes the investigation of lymphocytic infiltrates of atropic parapsoriasis, lymphomatoid papulosis, and a small group of miscellaneous skin conditions with OKT 6 and the immunoperoxidase technic. OKT 6-positive cells were identified in the dermis in varying numbers in four cases of atrophic parapsoriasis and in one case of lymphomatoid papulosis, but not in any of the other disorders. Positive epidermal staining was noted in all tissues examined. The pattern obtained suggested that epidermal dendritic cells may react with OKT 6. The findings indicate that OKT 6-positive cells may be found outside the thymus in certain conditions. The observations in epidermis cast doubt on the exact nature of the positively reacting cells observed in dermis, suggesting that may either be immature thymocytes or possibly Langerhans cells.

Antibodies↗
PubMed1981

The nosology of parapsoriasis.

Parapsoriasis is a group of uncommon but not rare disorders that was created in 1902 as part of a now long forgotten scheme to classify all inflammatory dermatoses. This artificial grouping has led to an enormously confused nosology of these disorders, that are, for the most part, otherwise unrelated. The use of a number of different terms at different institutions and by different physicians to denote the same diseases, together with the use of particular, single terms to denote different diseases, has caused much unnecessary confusion. In this review these terms are examined and an attempt is made to propose a new, unambiguous classification. Using this system, physicians with different views regarding which of the parapsoriases constitute distinct entities should have not difficulty communicating, and should have clearer frame of reference within which to work. An attempt is made to evaluate critically which of the parapsoriases are distinct entities and whether one or more of them should be considered an early form of cutaneous lymphoma in light of currently available data.

Atrophy↗
PubMed1981

HLA-DR-positive cells in large plaque (atrophic) parapsoriasis.

The development of a monoclonal antibody directed against HLA DR (Ia-like) antigens of B cells and monocytes but not against normal peripheral human T cells suggested that this antibody might be used as a marker of B cells and monocytes in tissue sections. The T cell nature of large plaque (atrophic) parapsoriasis has recently been demonstrated by the immunoperoxidase technic. Immunoperoxidase examination of serial sections of tissues from two cases of large plaque parapsoriasis with one T cell antiserum, two monoclonal T cell antibodies, and one monoclonal reagent directed against HLA DR indicated that T cells in the cutaneous infiltrates were also HLA DR-positive. Evidence is accumulating that HLA DR positivity may be expressed by activated T cells. The findings here therefore suggest that many of the T lymphoid cells in two cases of large plaque (atrophic) parapsoriasis examined were activated in nature, and that HLA DR may not be a specific marker for B cells and monocytes in certain pathologic conditions. Caution should therefore presently be exercised in attempting to use this marker for the specific identification of B cells and monocytes in pathologic specimens, without simultaneous testing for T cell markers.

Atrophy↗
PubMed1981

Identification of T-lymphocytes and T-subsets in human tonsil using monoclonal antibodies and the immunoperoxidase technic.

A study was performed using monoclonal antibodies and the immunoperoxidase technic to identify T-cells and T-subsets in human tonsil sections. The in situ topographic identification of T-cells, helper cells, and suppressor cells was achieved. This model may therefore be applied to other normal lymphoid tissues. Its potential pathologic importance lies in the fact that certain disorders may be associated with depletion of lymphocyte subsets from their normal areas of "homing," and that lymphoma cells may mirror their putative normal counterparts in their selective metastatic migration pattern. The improved knowledge of normal lymphocyte subset microenvironment afforded by this technic may therefore be of value in applied pathology.

Adolescent↗
PubMed1981

Demonstration in situ of "T" cells and "T" cell subsets in lichen planus using monoclonal antibodies.

This report describes the in situ demonstration of "T" lymphocytes and "T" lymphocyte subsets in tissue sections using a case of lichen planus as a model. The technique utilized is the indirect immunoperoxidase method with monoclonal antibodies to "T" cells and "T" cell subsets. In the case examined a predominance of helper "T" cells was found. The potential application of this method in the immunopathology of skin and internal organs is discussed.

Antibodies, Monoclonal↗
PubMed1981

T cell nature of exocytic and dermal lymphoid cells in atrophic parapsoriasis demonstrated by monoclonal Leu 1 and affinity isolated antibodies.

Tissues from atrophic large plaque parapsoriasis were examined using the indirect immunoperoxidase technique with a monoclonal T cell antibody as primary antibody, and affinity isolated peroxidase conjugated goat anti-mouse IgG as second stage antibody. The "T" cell nature of the dermal infiltrate and of single exocytic epidermal lymphocytes was demonstrated. The results obtained suggest that the method utilized will be useful for the demonstration of lymphoid cell subpopulations in a variety of cutaneous disorders in which a lymphocytic infiltrate forms a significant component of the histopathology observed. This technique also has the potential of providing information on the topographic localization and differentiation of lymphocytes within the various levels of the skin. Certain technical manipulations which may result in an improvement in the quality of results obtained are also discussed.

Antibodies, Monoclonal↗
PubMed1979

Subcutaneous fat necrosis in pancreatitis.

A case of subcutaneous fat necrosis as the initial manifestation of an attack of acute pancreatitis is presented. The accompanying features of respiratory distress syndrome, leukemoid reaction, shock, pleural effusions, and arthritis due to necrosis of periarticular fat are described. Autopsy findings are pancreatic pseudocyst, serofibrinous peritonitis, pleuritis, and pericarditis and fat necrosis not only in the subcutaneous fat but also in the pericardial, pleural, mediastinal, mesenteric, retroperitoneal, and pericalyceal fat.

Acute Disease↗
PubMed1977

Academic manpower in dermatology.

A survey showed that there were 338 strict or geographic full-time dermatologist faculty members in the United States. Ninety-six percent of these 338 faculty members were located at the 72 schools of medicine with residency training programs in dermatology or at the 21 approved residency training programs in dermatology, not affiliated with colleges of medicine. The 42 schools of medicine without approved residency training programs in dermatology reported only 11 full-time dermatologist faculty (3% of the total). Women constituted 7% of the faculty, while foreign medical graduates constituted 9%. More than one third of faculty were trained at the institution in which they currently serve. Approximately one third were likewise trained at four major teaching institutions.

Adult↗
PubMed1975

Epidermal apoptosis: cell deletion by phagocytosis.

Apoptosis is a process found in many tissues by which devitalized cells are eliminated in an orderly manner. In skin, apoptosis occurs following sunburn, in Bowen's disease and in basal cell carcinoma. Scattered cells are observed in which the cytoplasm has become condensed and dyskeratotic. These dyskeratotic cells are phagocytized, either in toto or in fragments by surrounding keratinocytes. This process involves the condensation, fragmentation, phagocytosis and digestion of individually degenerated cells. The mass of a tissue is thus related to the balance between cell formation (mitosis) and cell destruction (apoptosis). In epidermal and other surface tissues, the rate of exfoliation must also be considered.

Bowen's Disease↗
PubMed1975

Diminished erythroid ferrochelatase activity in protoporphyria.

In two patients with protoporphyria the enzymatic synthesis of aminolevulinic acid and prophobilinogen in erythroid tissue was normal. Boine marrow ferrochelatase activity was less than one-fourth of the mean activity in normal control subjects. Ferrochelatase activity in peripheral blood reticulocytes was less than 10% of controls. This metabolic abnormality provides one biochemical explanation for the increased concentrations of blood protoporphyrin in protoporphyria and clarifies the apparent minimally impaired hemoglobin synthesis in the two case studies.

5-Aminolevulinate Synthetase↗