megakaryocyte


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megakaryocyte

 [meg″ah-kar´e-o-sīt″]
the giant cell of bone marrow; it is a large cell with a greatly lobulated nucleus, and is generally supposed to give rise to blood platelets.

meg·a·kar·y·o·cyte

(meg'ă-kar'ē-ō-sīt),
A large cell (as much as 100 mcm in diameter) with a polyploid nucleus that is usually multilobed; megakaryocytes are normally present in bone marrow, not in the circulating blood, and give rise to blood platelets.
[mega- + G. karyon, nut (nucleus), + kytos, hollow vessel (cell)]

megakaryocyte

(mĕg′ə-kăr′ē-ō-sīt′, -ə-sīt′)
n.
A large bone marrow cell with a lobulate nucleus that gives rise to blood platelets.

megakaryocyte

A very large cell native to the bone marrow which is the precursor of platelets and the largest (40–100 µm in diameter) normal nucleated haematopoietic cell in the marrow. Megakaryocytes may be relatively small (micromegakaryocytes) and measure 15–30 µm in diameter. The nucleus usually has multiple (8, 16 or 32) overlapping lobes; megakaryocytes with few (2 or 4) lobes may occur in myelodysplasia. Nucleoli are absent, chromatin is coarse, cytoplasm is abundant, stains light blue or pink, and contains numerous purplish-red or pink granules. The N:C ratio is 1:1 to 1:2. Megakaryocytes producing platelets may reveal demarcated granular clumps of platelets extruding/streaming from the margins (platelet budding).

meg·a·kar·y·o·cyte

(meg'ă-kar'ē-ō-sīt)
A large cell with a multilobed nucleus; normally present in bone marrow, not in the circulating blood; gives rise to blood platelets (thrombocytes).
Synonym(s): megalokaryocyte.
[mega- + G. karyon, nut (nucleus), + kytos, hollow vessel (cell)]
Enlarge picture
MEGAKARYOCYTE: (Orig. mag. ×640)
Enlarge picture
MEGAKARYOCYTE

megakaryocyte

(meg?a-kar'e-o-sit?) [? + karyon, nucleus, + kytos, cell]
Large bone marrow cell with large or multiple nuclei from which platelets are derived.
See: platelet; illustrationillustration

megakaryocyte

An unusually large bone marrow cell that releases many small fragments of its CYTOPLASM as the blood PLATELETS essential for clotting (blood coagulation).

Megakaryocyte

A large bone marrow cell with a lobed nucleus that is the precursor cell of blood platelets.
References in periodicals archive ?
Blood platelets are released by bigger vessel-penetrating protrusions of huge, largely immobile progenitor cells, named megakaryocytes.
Although autoantibody-mediated destruction of platelets in the peripheral circulation has been considered the chief mechanism of SLE-related thrombocytopenia, impaired platelet production by megakaryocytes in the bone marrow mediated by autoantibodies might be more important in some patients.
Stat3 (signal transducer and activator of transcription) phosphorylates, forms dimers, translocates to the nucleus, regulates gene transcription, and regulates megakaryocyte and platelet production and apoptosis [9].
We further analyzed the association between the distribution of NF-[kappa]B-94ins/del ATTG and megakaryocytes in ITP patients, and no correlation was found between them (p = 0.085, Figure 1(b)).
In megakaryocyte polyploidization, the cell cycle-related protein and cytoskeletal proteins both play important role in MK endomitosis.
Shen et al., "Sympathetic stimulation facilitates thrombopoiesis by promoting megakaryocyte adhesion, migration, and proplatelet formation," Blood, vol.
Alternatively, this risk factor may urge the megakaryocytes to autonomously overproduce platelets without increased platelet consumption [36].
Megakaryocyte potentiation factor cleaved from mesothelin precursor is a useful tumor marker in the serum of patients with mesothelioma.
We speculate that the unfavourable response to splenectomy in patients with steroid-resistant disease is possibly due to greater megakaryocyte dysfunction, in addition to increased peripheral consumption.
4, A-C, individuals with EMV mRNA recovery by day 15 all showed data points above this 45[degrees] dotted line, indicating that EMV mRNA recovery was earlier than that for CBC for all 3 lineages, myeloid, erythroid, and megakaryocyte. By contrast, the EMV mRNA data were not conclusive if mRNA recovery occurred after day 15.
The mesothelin gene is located on chromosome 16p13.3 and encodes at least four protein products, including megakaryocyte potentiating factor (MPF) [13, 14] and three isoforms of mesothelin, which are variant 1 (mesothelin) [14], the currently uncharacterized variant 2 [15, 16], and variant 3 (soluble-mesothelin-related protein (SMRP)) [17].