Mitotic index

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Mitotic index is a measure for the proliferation status of a cell population. It is defined as the ratio between the number of cells in mitosis and the total number of cells.

Purpose[edit]

The mitotic index is an important prognostic factor predicting both overall survival and response to chemotherapy in most types of cancer. It may lose much of its predictive value for elderly populations, for example a low mitotic index loses any prognostic value for women over 70 years old with breast cancer.[1]

Additionally, the mitotic index is simply a measurement to determine the percentage of cells undergoing mitosis. Mitosis is the division of somatic cells when genetic information from one single cell is equally dispersed into two daughter cells. Durations of the cell cycle and mitosis vary in different cell types. An elevated mitotic index indicates more cells are dividing, and thus obvious in cancer cells, The mitotic index may be elevated during necessary processes to life, such as the normal growth of plants or animals, as well as cellular repair the sire of an injury.[2]

Calculation[edit]

Mitotic index can be calculated using the following operation : cells observed with visible chromosomes ÷ total number of cells visible.[3]

References[edit]

  1. ^ Baak, J. P. A.; Gudlaugsson, E.; Skaland, I.; Guo, L. H. R.; Klos, J.; Lende, T. H.; Søiland, H. V.; Janssen, E. A. M.; Zur Hausen, A. (2008). "Proliferation is the strongest prognosticator in node-negative breast cancer: Significance, error sources, alternatives and comparison with molecular prognostic markers". Breast Cancer Research and Treatment 115 (2): 241–254. doi:10.1007/s10549-008-0126-y. PMID 18665447.  edit
  2. ^ Urry et al. (2014). Campbell Biology in Focus. Pearson. 
  3. ^ Edexcel practical materials created by Salters-Nuffield Advanced Biology, copyright University of York Science Education Group

External links[edit]