Monday, August 15, 2011

Advancing the Vocab

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S-phase Fraction

Definition: (S faze FRAK-shun) A measure of the percentage of cells in a tumor that are in the phase of the cell cycle during which DNA is synthesized. The S-phase fraction may be used with the proliferative index to give a more complete understanding of how fast a tumor is growing. See mitosis.

Proliferative Index [Synonyms: proliferation index]

Definition: A measure of the number of cells in a tumor that are dividing (proliferating). May be used with the S-phase fraction to give a more complete understanding of how fast a tumor is growing.

Mitosis

Definition: (my-TOE-sis) The process of division (mitotic activity) of somatic cells in which each daughter cell receives the same amount of DNA as the parent cell.
(Phoenix5)

Phenotype

Definition: The appearance of an individual, which results from the interaction of the person's genetic makeup and his or her environment. By contrast, the genotype is merely the genetic constitution (genome) of an individual. For example, if a child's genotype includes the gene for osteogenesis imperfecta (brittle bone disease), minimal trauma can cause fractures. The gene is the genotype, and the brittle bones themselves are the phenotype. (Medicine.Net)

Diploid

Definition: noun - (Science: genetics, cell biology)
A cell or an organism consisting of two sets of chromosomes: usually, one set from the mother and another set from the father. In a diploid state the haploid number is doubled, thus, this condition is also known as 2n. adjective - Of or pertaining to a diploid, that is a cell or an organism with two sets of chromosomes.

Supplement - An example of a cell in a diploid state is a somatic cell. In humans, the somatic cells typically contain 46 chromosomes in contrast to human haploid gametes (egg and sperm cells) that have only 23 chromosomes.  (Biology-Online.org)

Angiogenesis:



 
noun. pl. an·gi·o·gen·e·ses
The formation of new blood vessels.
  • The development of blood vessels is an essential step in tumor growth.
  • A tumor cannot grow larger than a fraction of an inch without a blood supply.
  • Tumor cells produce or cause other cells to produce growth factors that stimulate blood vessel formation.

Angiogenesis Inhibitors:

noun ~ A drug that blocks angiogenesis in cancerous tissue, thus interfering with tumor growth or metastasis.
  • Some cells produce naturally occurring inhibitors of angiogenesis.
  • These inhibitors are a focus of research as possible cancer treatments.
  • Several anti-angiogenesis cancer drugs are already on the market and more are being tested.
  • Angiogenesis inhibitors have two main benefits as a treatment:

    1. They should be less toxic than conventional chemotherapy.
    2. Because they target normal cells and not the cancer cells themselves, they should be less likely to lead to the selection of drug-resistant tumors.

Metastasis
  • Metastasis is the process by which cancer cells spread to distant locations in the body.
  • The majority of death associated with cancer is due to the metastasis of the original tumor cells.
  • Metastasizing cancer cells must secrete a mixture of digestive enzymes in order to degrade barriers.
  • Cancer cells may use the circulatory system to move to a suitable location to settle.
  • Metastasis is a very inefficient process. Most cancer cells die once they leave the original tumor.

Lymphatic Metastasis
  • Cancer can use the lymphatic system as well as the circulatory system to metastasize.
  • The movement of cancer cells via the lymphatic system into lymph nodes is used in the detection of metastatic disease and tumor staging.






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