null cell


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null cell

Etymology: L, nullus, not one, cella, storeroom
a lymphocyte that develops in the bone marrow and lacks the characteristic surface markers of the B and T cells (surface immunoglobulin or the pan-T antigen). Null cells represent a small proportion of the lymphocyte population. Stimulated by the presence of an antibody, null cells can attack certain cellular targets directly. They kill tumor or viral-infected cells, although not with the specificity of cytotoxic T cells. A null cell is a type of natural killer cell. Compare B cell, T cell. . See also cytotoxin, immune gamma globulin. The term null cell is no longer in common use.

null cell

A large lymphocyte without the cell markers of either a T cell or a B cell. Natural killer cells are examples of null cells.
See also: cell

null cell,

n a lymphocyte that develops in the bone marrow and lacks the characteristic surface markers of the B and T lymphocytes. Null cells stimulated by the presence of antibody can directly attack certain cellular targets and are known as “natural killers” or “killer cells.”

null

an absence of information, as contrasted with zero or blank or nil, about a value.

null cell
called also null lymphocyte; see null cell.
null hypothesis
a statistical hypothesis which states that one variable has no association with another variable, or set of variables. That is, the observed results can be explained by chance alone.
null lymphocyte
see null cell.
References in periodicals archive ?
Abbreviations: ACTH, adrenocorticotroph adenoma; GH, growth hormone adenoma; GH+, Pit-1 family member with strong growth hormone and a lesser degree of prolactin or thyroid-stimulating hormone (TSH) staining; Gon, gonadotroph adenoma; Null, null cell adenoma; Pit1, Pit-1 family member (not otherwise specified); PlurGH, plurihormonal growth hormone adenoma; PlurGH+, plurihormonal growth hormone adenoma with lesser degrees of prolactin or TSH staining; PRL, prolactinoma; PRL+, Pit-1 family member with strong prolactin staining and lesser degree of growth hormone or thyrotropin staining; TSH+, TSH-producing adenoma with lesser degree of GH staining; Unk, unknown.
c, Occasional gonadotroph/ null cell adenomas will demonstrate clustering of cells, paralleling the perivascular pseudorosette-like formation that can occur on permanent sections.
1 dagger]) dagger]) Anaplastic large T-cell lymphoma 1 0 0 Anaplastic large null cell lymphoma 2 0 0 Diffuse large B-cell lymphoma 9 ([double 3 ([double 9.