Lymphoblast

A lymphoblast is a modified naive lymphocyte with altered cell morphology. It occurs when the lymphocyte is activated by an antigen (from antigen-presenting cells) and increased in volume by nucleus and cytoplasm growth as well as new mRNA and protein synthesis. The lymphoblast then starts dividing two to four times every 24-hours for 3-5 days, with a single lymphoblast making approximately 1000 clones of its original naive lymphocyte, with each sharing the originally unique antigen specificity. Finally the dividing cells differentiate into effector cells, known as Plasma Cells (for B cells), Cytotoxic T cells, and Helper T cells.[1]

Lymphoblast

Lymphoblasts can also refer to immature cells which typically differentiate to form mature lymphocytes.[2] Normally lymphoblasts are found in the bone marrow, but in acute lymphoblastic leukemia (ALL), lymphoblasts proliferate uncontrollably and are found in large numbers in the peripheral blood.

The size is between 10 and 20 μm.[3]

Although commonly lymphoblast refers to a precursor cell in the maturation of leukocytes, the usage of this term is sometimes inconsistent. The Chronic Lymphocytic Leukemia Research Consortium defines a lymphoblast as "A lymphocyte that has become larger after being stimulated by an antigen. Lymphoblasts look like immature lymphocytes, and were once thought to be precursor cells."[4] Commonly, when speaking about leukemia, "blast" is used as an abbreviation for lymphoblasts.

Lymphoblasts can be distinguished microscopically from myeloblasts by having less distinct nucleoli, more condensed chromatin, and an absence of cytoplasmic granules. However these morphologic distinctions are not absolute and a definitive diagnosis relies on antibody immunostaining for the presence of unique cluster of differentiation receptors.[5]

Additional images
  • Blood cell lineage
gollark: Okay, very hacky but technically workable: have an XTMF metadata block of a fixed size, and after the actual JSON data, instead of just ending it with a `}`, have enough spaces to fill up the remaining space then a `}`.
gollark: XTMF was not really designed for this use case, so it'll be quite hacky. What you can do is leave a space at the start of the tape of a fixed size, and stick the metadata at the start of that fixed-size region; the main problem is that start/end locations are relative to the end of the metadata, not the start of the tape, so you'll have to recalculate the offsets each time the metadata changes size. Unfortunately, I just realized now that the size of the metadata can be affected by what the offset is.
gollark: The advantage of XTMF is that your tapes would be playable by any compliant program for playback, and your thing would be able to read tapes from another program.
gollark: Tape Shuffler would be okay with it, Tape Jockey doesn't have the same old-format parsing fallbacks and its JSON handling likely won't like trailing nuls, no idea what tako's program thinks.
gollark: Although I think some parsers might *technically* be okay with you reserving 8190 bytes for metadata but then ending it with a null byte early, and handle the offsets accordingly, I would not rely on it.

See also

References
  1. Janeway's Immunobiology, 9th edition, Chapter 1, page 23
  2. Information, National Center for Biotechnology; Pike, U. S. National Library of Medicine 8600 Rockville; MD, Bethesda; Usa, 20894. "Lymphoblasts - National Library of Medicine". PubMed Health. Retrieved 2015-11-17.CS1 maint: numeric names: authors list (link)
  3. Gillian Rozenberg (23 March 2011). Microscopic Haematology: A Practical Guide for the Laboratory. Elsevier Australia. pp. 106–. ISBN 978-0-7295-4072-8. Retrieved 29 May 2011.
  4. CRC - Glossary L Archived 2006-02-11 at the Wayback Machine
  5. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon C. (2010). Robbins and Cotran Pathologic Basis of Disease. Philadelphia: Saunders. p. 602. ISBN 978-1-4160-3121-5. 8th edition.


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