| acceleration phase | <cell biology, cell culture> A period of increasing growth before the log phase in a culture of microbes. After the culture is started on a medium, at first there is no growth (the lag phase) and then the microbes start to gradually grow (acceleration phase) until they reach a constant maximum rate of growth (log phase). (15 Jan 1998) |
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| acute-phase protein | <haematology> These plasma proteins (in addition to fibrinogen) increase 25% or more in response to inflammation and injury are under direct control of interleukin-6 (IL-6) (hepatocyte-stimulating factor). Other proteins which increase are ceruloplasmin, C3 and C4 which increase 50% or more; alpha-1 acid glycoprotein, alpha-1 antitrypsin, haptoglobin and fibrinogen (the major determinant of viscosity 1 ) which increase two- to fourfold; C-reactive protein (CRP) and serum amyloid A which increase several hundred-fold. Despite long-held clinical opinion to the contrary, available data indicate that neither ESR nor measurement of specific acute-phase reactants are useful in excluding underlying infection or inflammation regardless of the pretest probability. These proteins are secreted into the blood in increased or decreased quantities by hepatocytes in response to trauma, inflammation, or disease. They can serve as inhibitors or mediators of the inflammatory processes. Certain acute-phase proteins have been used to diagnose and follow the course of diseases or as tumour markers. See also: amyloid, c-reactive protein, erythrocyte sedimentation rate, viscosity. (25 Jun 1999) |
| acute-phase reaction | <immunology, rheumatology> Refers to the changes in synthesis of certain proteins within the serum during an inflammatory response, which provides rapid protection for the host against microorganisms via non-specific defense mechanisms. It consists of fever, an increase in inflammatory humoral factors, and an increased synthesis by hepatocytes of a number of proteins or glycoproteins usually found in the plasma; the reaction is mediated by endogenous pyrogens, the hypothalamus, adrenal hormones, and other factors. (12 Jul 2000) |
| anal phase | In psychoanalytic personality theory, the stage of psychosexual development, occurring when a child is between 1 and 3 years, during which activities, interests, and concerns are centreed around the anal zone. (05 Mar 2000) |
| aqueous phase | The water portion of a system consisting of two liquid phase's, one mainly water, the other a liquid immiscible with water (e.g., benzene, ether). (05 Mar 2000) |
| blast phase | Refers to advanced chronic myelogenous leukaemia. In this phase, the number of immature, abnormal white blood cells in the bone marrow and blood is extremely high. Also called blast crisis. (12 Dec 1998) |
| g0 phase | Phase of the cell cycle where cells exist in a quiescent state. These cells have unduplicated DNA, degraded RNA and protein, and low enzyme activity. The ability to switch between g0 and g1 (and vice versa) determines the post-embryonic cell proliferation rate and is defectively controlled in neoplastic cells. (12 Dec 1998) |
| g1 phase | <cell biology, molecular biology> The period during interphase in the cell cycle between mitosis and the S phase (when DNA is replicated). Also known as the decision period of the cell, because the cell decides to divide when it enters the s phase. The G stands for gap. (09 Oct 1997) |
| g2 phase | <cell biology, molecular biology> The period during interphase in the cell cycle between the S phase (when DNA is replicated) and mitosis (when the nucleus, then cell, divides). at this time, the cell checks the accuracy of DNA replication and prepares for mitosis. The G stands for gap. (09 Oct 1997) |
| radial growth phase | The early pattern of growth of cutaneous malignant melanoma, in which tumour cells spread laterally in the epidermis. (05 Mar 2000) |
| Gap1 phase | The period of the cell cycle after cell division when there is synthesis of RNA and protein; it may last for a few hours in rapidly growing tissue or a lifetime in non-renewing cells such as nerve cells. Synonym: Gap1 phase, postmitotic phase. (05 Mar 2000) |
| Gap2 phase | The period in the cell cycle when synthesis of DNA is completed but before mitosis begins. Synonym: Gap2 phase, premitotic phase. (05 Mar 2000) |
| genital phase | In psychoanalytic personality theory, the final stage of psychosexual development, occurring during puberty, in which the individual's psychosexual development is so organised that sexual gratification can be achieved from genital-to-genital contact and the capacity exists for a mature affectionate relationship with an individual of the opposite sex. See: phallic phase. (05 Mar 2000) |
| vertical growth phase | Spread of melanoma cells from the epidermis into the dermis and later the subcutis, from which site metastasis may take place. (05 Mar 2000) |
| Gibb's phase rule | An expression of the relationships existing between systems in equilibrium: P + V = C + 2, where P is the number of phases, V the variance or degrees of freedom, and C the number of components; it also follows that the variance is, V = C + 2 -P. For H2O at its triple point, V = 1 + 2 -3 = 0, i.e., both temperature and pressure are fixed. Synonym: Gibb's phase rule. (05 Mar 2000) |