Help from T Cells

Immunophenotypic markers of monoclonal T-cell proliferations have not been identified. However, subtle alterations in broadly active T-cell selective ( pan-T-cell ) determinants may be helpful in selected cases. Cutaneous T-cell lymphomas (CTCL) characteristically express aberrant phenotypes, represented either by the relative absence of the pan-T-cell markers CD3, CDS, CD43, and CD7 (especially the last of those) or by the concordant expression or loss of both CD4 and CDS (Fig. 13.19).i 454 xhose results are not expected in most mature reactive (benign) T-cell populations. 455,156 Unfortunately, some examples of CTCL fail to exhibit aberrant phenotypes, limiting the value of these attributes in the separation of such lymphomas from T-cell-rich dermatitides,i 455 and, conversely,... 

In addition to antibodies, the immune system also consists of bone-marrow derived lymphocytes, or B cells, and T cells that come from the thymus gland, both of which (indirectly) produce antibodies. These cells, in turn, may be helped by helper cells (= H) and suppressed by suppressor cells (= S). Helper cells may be alarmed as to the presence of antigens by macrophages (= M) that eat the antigens and leave parts of their meal on their cell surface. 

Mechanism of Action An immunologic agent that interferes with the activation of T-lymphocytes by binding to the lymphocyte antigen, thus reducing the number of circulating T-lymphocytes. Therapeutic Effect Prevents T cells from becoming overactive, which may help reduce symptoms of chronic plaque psoriasis. Pharmacokinetics Half-life 270 hr... 

Carl T. Grimm, 20, a sophomore from Placentia, Calif., swallowed a crystalline form of potassium cyanide, which prevents oxygen from entering cells. He immediately asked his roommate to call for help but not before the chemical reacted with water in his body and began to produce cyanide gas, a spokesman for the college said. 

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