The mitotic index (percentage of cells in mitosis at any time) provides a measure of the capacity of cells to divide and of the rate of cell division. It is used to identify the sites of growth within a tissue and to determine which cell types are dividing.
What is the importance of mitotic index?
In cancer cells, the mitotic index may be elevated compared to normal growth of tissues or cellular repair of the site of an injury. The mitotic index is therefore an important prognostic factor predicting both overall survival and response to chemotherapy in most types of cancer.
What is considered a high mitotic index?
The mitotic thresholds, as suggested by Perry and coworkers,3 were adopted by the WHO as an objective grading criterion: benign (WHO grade I) menin- giomas do not exceed 4 mitoses per 10 HPF, atypical (WHO grade II) meningiomas exhibit an MI of 4 or more and fewer than 20, and anaplastic (WHO grade III) meningiomas …
What is normal mitotic index?
The total mitotic index represents the total number of normal and abnormal mitotic figures per 10 high-power fields of the most mitotically active area for a given specimen. As noted previously, the endometrial maturation phase was used as a surrogate indicator of the hormonal status.
How is mitotic index used in medicine?
The mitotic index is used for tumor grading of breast and ovarian cancers [8,9]. In addition, mitotic index has been incorporated in the American Joint Committee on Cancer (AJCC) seventh tumor staging system for malignant melanoma, gastrointestinal tumor, and neuroendocrine tumors of the gastrointestinal tract .
Do benign tumors have a high mitotic index?
Occasionally, the mitotic rate in benign tumors may be brisk, and those with mitotic activity up to 15 mitoses/10 hpf are termed leiomyomata with increased mitotic activity (Fig. 20.81; see Table 20.7).
What is high mitotic activity?
Listen to pronunciation. (my-TAH-tik ak-TIH-vih-tee) Having to do with the presence of dividing (proliferating) cells. Cancer tissue generally has more mitotic activity than normal tissues.
Does caffeine affect mitosis?
Overall, most research data indicate that caffeine does indeed reverse DNA-damage-induced G2 arrest and drive cells through a fatal mitosis. Many reports suggested that the mechanism may be related to caffeine’s ability to reactivate Cdc2 and Cdc25C activities.
Does temperature affect mitosis?
The relative change in the duration of mitosis and of interphase are shown to differ with change in temperature. … The rate of cell progress, or mitotic rate, throughout the mitotic cycle increases linearly with increase in temperature between the range 3 °C to 25 °C.
How do environmental factors affect mitosis?
With environmental factors, such as rainfall or lectin protein, mitosis is induced in some root apical meristem tissues. Lectin is a protein found in soil near roots, which stimulates the rapid division of cells. … This is a simple example of abiotic factors in the environment affecting plant growth.