Untitled - D Ank Unlimited

myelogenous leukemia 520 myocardial autoantibodies (MyAs)
develop as a consequence of ineffective hematopoiesis
marked by abnormal myeloid, erythroid, and megakaryocytic
precursors and may develop into acute myeloid
leukemia (AML).
myelogenous leukemia
A myeloid lineage cell malignancy.
myeloid antigen
A surface epitope of myeloid leukocytes. Examples include
CD13, CD14, and CD33. A poor prognosis is indicated
when the leukocytes of a patient with acute lymphocytic
leukemia express myeloid antigens. Their expression is a
better indicator of decreased survival than are other features
of the disease.
myeloid cells
Cells that arise from common myeloid progenitors, comprising
erythrocytes, neutrophils, monocyte/macrophages,
eosinophils, basophils, and megakaryocytes.
myeloid cell series
An immature bone marrow cell (myeloblast) that is a
precursor of the polymorphonuclear leukocyte series. This
18-μm diameter cell has a relatively large nucleus with
finely distributed chromatin and two conspicuous nucleoli.
The cytoplasm is basophilic when stained. During maturation,
the cytoplasm becomes populated with large azurophilic
primary granules, representing the promyelocyte
stage. Later, the specific or secondary granules appear,
representing the myelocyte stage. The nucleoli vanish as the
nuclear chromatin forms dense aggregates. The chromatin
in the nucleus condenses, and the cells no longer divide at
this metamyelocyte stage. The nucleus assumes a sausagelike
configuration known as a band. This subsequently
develops into a three-lobed polymorphonuclear leukocyte
that subsequently becomes a neutrophil, eosinophil, or
basophil of the myeloid cell group. All three types of
myeloid cells are present in normal peripheral blood.
myeloid lineage
A bone marrow-derived subset of cells, including granulocytes,
monocytes, and macrophages.
myeloid progenitors
Bone marrow stem cells that lead to the formation of granulocytes,
monocytes, and macrophages.
myeloma
A plasma cell dyscrasia characterized by highly malignant
plasma cells in solid masses or dispersed as clones in the
bone marrow. A plasmacytoma represents proliferation
of a neoplastic plasma cell clone in bone marrow with the
production of a monoclonal immunoglobulin paraprotein
in addition to Bence–Jones proteins (free Ig light chains).
Besides myeloma in humans, an experimental variety can
be induced in certain inbred mouse strains such as BALB/c
by intraperitoneal injection of mineral oil.
myeloma, IgD
A myeloma in which the monoclonal immunoglobulin is
IgD. It constitutes 1 to 2% of myelomas and usually occurs
in older males. Lymphadenopathy and hepatosplenomegaly
are present. Approximately one half of the cases develop
dissemination beyond the bones. Patients develop osteolysis,
hypercalcemia, anemia, azotemia, aberrant plasma
cells, and plasma blasts.
myeloma protein
The immunoglobulin synthesized in excess in patients with
multiple myeloma (plasmacytoma). Myeloma proteins are
products of proliferating plasma cells of a malignant clone.
The heavy and light chains are usually assembled to produce
the homogeneous monoclonal paraimmunoglobulin,
but if the synthesis of light chains is exclusive or exceeds
that of heavy chains, a Bence–Jones protein may appear in
addition to the paraimmunoglobulin or it may occur alone.
A myeloma protein may be a whole molecule of monoclonal
immunoglobulin or part of the molecule synthesized by
malignant plasma cells.
myelomatosis
A condition in which bone marrow plasma cells undergo
malignant transformation and produce excessive homogeneous
monoclonal immunoglobulin molecules that represent
a paraprotein of a specific immunoglobulin isotype
such as IgG or IgA. IgD and IgE myelomas also occur.
Serum electrophoresis reveals a clearly demarcated band.
Isoelectric focusing shows a classic monoclonal banding
pattern. Some patients also have Bence–Jones protein in
their urine. Patients are often males past 50 years of age
and commonly present with spontaneous bone fracture or
anemia due to replacement of bone marrow.
myeloperoxidase
An enzyme present in the azurophil granules of neutrophilic
leukocytes that catalyzes peroxidation of many
microorganisms. Myeloperoxidase, in conjunction with
hydrogen peroxidase and halide, has a bactericidal effect.
myeloperoxidase (MPO) deficiency
A lack of 116-kDa myeloperoxidase in both neutrophils
and monocytes. This enzyme is located in the primary
granules of neutrophils. It possesses a heme ring that
imparts a dark green tint to the molecule. MPO deficiency
has an autosomal-recessive mode of inheritance. Affected
patients have a mild version of chronic granulomatous
disease. Candida albicans infections are frequent in this
condition.
myelopoiesis
The generation of descendant myeloid lineage cells from
hematopoietic stem cells differentiating into common
myeloid progenitors in the bone marrow.
myeloproliferative diseases (MPD)
Chronic hematopoietic neoplasms of myeloid lineage cells,
including chronic myelogenous leukemia (CML), polycythemia
vera, essential thrombocythemia, and myelofibrosis.
myocardial antibodies
Antibodies against myocardium that have been demonstrated
in two thirds of coronary artery bypass patients
and in Dressler syndrome. Patients with acute rheumatic
fever often manifest myocardial antibodies reactive with
sarcolemmal, myofibrillar, or intermyofibrillar targets.
Dilated cardiomyopathy patients and patients with systemic
hypertension/autoimmune polyendocrinopathy may develop
autoantibodies against myocardium.
myocardial autoantibodies (MyAs)
Myocardial autoantibody titers increase in approximately
two thirds of coronary artery bypass patients, but this is not
necessarily related to postcardiotomy syndrome. MyAs with
sarcolemmal, intermyofibrillar patterns are demonstrable
in most acute rheumatic fever patients. Their molecular
mimicry is believed to have a role in pathogenesis. The sera
of patients with idiopathic dilated cardiomyopathy react
with the adenine nuclear translocator protein, a mitochondrial
branched chain α-ketoacid dehydrogenase, cardiac β