| LEF | leukokinesis-enhancing factor; lupus erythematosus factor; lymphoid-enhanced binding factor |
|---|---|
| LIF | laser-induced fluorescence; left iliac fossa; left index finger; leukemia-inhibiting factor; leukocy... |
| MF | magnetic field; meat free; medium frequency; megafarad; membrane filler; merthiolate-formaldehyde [s... |
| MSF | macrophage slowing factor; macrophage spreading factor; Medicins sans Frontieres [Doctors without Bo... |
| SPF | skin protection factor; specific-pathogen free; spectrophotofluorometer; S-phase fraction; split pro... |
| nuclear warfare | Warfare involving the use of nuclear weapons. (12 Dec 1998) |
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| nucleolar-nuclear ratio | Ratio of volume of nucleolus to volume of nucleus, usually increased in malignant neoplasms. (05 Mar 2000) |
| direct nuclear division | <cell biology> An unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell without chromosome condensation or spindle formation. Partitioning of daughter chromosomes is haphazard. Observed in some Protozoa. (18 Nov 1997) |
| indirect nuclear division | <cell biology> A method of indirect division of a cell, consisting of a complex of various processes, by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes characteristic of the somatic cells of the species. Mitosis, the process by which the body grows and replaces cells, is divided into four phases. 1. Prophase: formation of paired chromosomes, disappearance of nuclear membrane, appearance of the achromatic spindle, formation of polar bodies. 2. Metaphase: arrangement of chromosomes in the equatorial plane of the central spindle to form the monaster. Chromosomes separate into exactly similar halves. 3. Anaphase: the two groups of daughter chromosomes separate and move along the fibres of the central spindle, each toward one of the asters, forming the diaster. 4. Telophase: the daughter chromosomes resolve themselves into a reticulum and the daughter nuclei are formed, the cytoplasm divides, forming two complete daughter cells. NOTE: the term mitosis is used interchangeably with cell division, but strictly speaking it refers to nuclear division, whereas cytokinesis refers to division of the cytoplasm. In some cells, as in many fungi and the fertilized eggs of many insects, nuclear division occurs within the cell unaccompanied by division of the cytoplasm and formation of daughter cells. (13 Nov 1997) |
| internal nuclear layer of retina | The intermediate layer of neurons in the retina composed largely of bipolar cells. Synonym: internal nuclear layer of retina, stratum ganglionare retinae, stratum nucleare internum retinae. (05 Mar 2000) |
| epstein-barr virus nuclear antigens | Nuclear antigens encoded by epstein-barr virus genes. at least six nuclear antigens have been identified but their mechanism of action and role in B-cell transformation is still unknown. (12 Dec 1998) |
| external nuclear layer of retina | The outermost layer of the cerebral layer of retina, composed of the primary receptor cells of the retina; the stratum consists of two sublayers: 1) an external layer made up of the rods and cones, the photosensitive processes of the receptor cells, and 2) the external nuclear layer containing the cell bodies of these cells; the external limiting membrane forms a perforated supporting plate between the two sublayers; the name refers to the fact that the retinal receptor cells are a specialised form of (epithelial) ependyma cell and thus, in a sense, are comparable to the neuroepithelial cells (e.g., hair cells) of other sense organs. Synonym: external nuclear layer of retina, stratum neuroepitheliale retinae, stratum nucleare externum retinae. (05 Mar 2000) |
| U1 small nuclear RNA-(guanosine-N2)-methyltransferase | <enzyme> A trans-active non-small nuclear ribonucleoprotein; facilitates the formation of the m3g cap Registry number: EC 2.1.1.- Synonym: u1 snrna(g-n2)mtase (26 Jun 1999) |
| U6 small nuclear RNA methyltransferase | <enzyme> Methylates gamma-phosphate residues in rnas; distinct from u6 snrna n6-adenosine methyltranferase; mw 130 kD; from hela cells Registry number: EC 2.1.1.- Synonym: u6 snrna capping enzyme (26 Jun 1999) |
| accelerator factor | <chemical> Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor v accomplishes this by forming a complex with factor xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor v leads to owren's disease. Chemical name: Blood-coagulation factor V (12 Dec 1998) |
| acetate replacement factor | <biochemistry> 1,2 dithiolane 3 valeric acid. Regarded as a coenzyme in the oxoglutarate dehydrogenase complex of the citric acid cycle. Involved generally in oxidative decarboxylations of _ keto acids. A growth factor for some organisms. (18 Nov 1997) |
| adrenal weight factor | A postulated substance of adenohypophysial origin responsible for maintenance of the weight of the adrenal cortex. (05 Mar 2000) |
| adrenocorticotropic releasing factor | Hormone produced by hypothalamus that causes pituitary to secrete adrenocorticotropic hormone. (05 Mar 2000) |
| a-factor | <molecular biology> A protein which is found in the bacterial genus Streptomyces that helps start the production of streptomycin and the process of morphological differentiation. It is used in biotechnology to induce these functions in mutant strains of Streptomyces that cannot produce it themselves. (09 Feb 1998) |
| angiogenesis factor | Substance causing proliferation of new blood vessels. It is found in tissues with high metabolic requirements, such as the retina, and in certain cancers. The factor is also released by hypoxic macrophages at the edges or outer surfaces of wounds and initiates revascularization in wound healing. (12 Dec 1998) |