| ABO incompatibility | <haematology> A type of blood incompatibility, found rarely. Transfusion reactions may occur as a result of such incompatibility. (27 Sep 1997) |
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| blood group incompatibility | A mismatch between donor and recipient blood. Antibodies present in the recipient's serum are directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is haemolyzed. (12 Dec 1998) |
| rhesus incompatibility | <haematology> A blood incompatibility between the mother and her baby. During childbirth if the mother is Rh negative and the baby is Rh positive, blood can enter the maternal circulation (from the baby) sensitising the mother against Rh factor. The mother's immune system will produce antibodies to Rh factor. In subsequent pregnancies, these maternal Rh antibodies can mix into the foetal circulation during childbirth. This will cause the rupture (haemolytic anaemia) of the baby's red blood cells. See: newborn jaundice. (27 Sep 1997) |
| physiologic incompatibility | A form of incompatibility in which the substances in a mixture exert opposing physiologic actions. Synonym: therapeutic incompatibility. (05 Mar 2000) |
| self incompatibility | <plant biology> Inability of pollen grains to fertilize flowers of the same plant or its close relatives. Acts as a mechanism to ensure out breeding within some plant species, for example in the case of the S gene complex in Brassicas. (18 Nov 1997) |
| drug incompatibility | <pharmacology> The quality of not being miscible with another given substance without a chemical change. One drug is not of suitable composition to be combined or mixed with another agent or substance. The incompatibility usually results in an undesirable reaction, including chemical alteration or destruction. (12 Dec 1998) |
| incompatibility | The quality of being incompatible. (05 Mar 2000) |
| therapeutic incompatibility | A form of incompatibility in which the substances in a mixture exert opposing physiologic actions. Synonym: therapeutic incompatibility. (05 Mar 2000) |
| relaxed plasmid | A plasmid that replicatesindependently of the main bacterial chromosome and is present in 10-500 copies per cell. (09 Oct 1997) |
| RNA plasmid | <molecular biology> DsRNA found in yeasts, also called killer factors. Their nomenclature is uncertain and some scientists consider them viruses. (23 Aug 1998) |
| R plasmid | <molecular biology> A plasmid that confers resistance to one or more antibiotics or other poisonous compounds in a bacterium. (17 Dec 1997) |
| plasmid | <molecular biology> A small, independently replicating, piece of extrachromosomal cytoplasmic DNA that can be transferred from one organism to another. Linear or circular DNA molecules found in both pro and eukaryotes capable of autonomous replication. Stringent plasmids occur at low copy number in cells, relaxed plasmids at high copy number, ca 10 to 30. Plasmids can become incorporated into the genome of the host or can remain independent. An example is the f factor of E. Coli. May transfer genes and plasmids carrying antibiotic resistant genes can spread this trait rapidly through the population. Described largely from bacteria and protozoa. Some plasmids are capable of integrating into the host genome. A number of artificially constructed plasmids are used as cloning vectors. (14 Oct 1997) |
| conjugative plasmid | Self-transmissible plasmid, a plasmid which encodes all the functions needed for its own intercellular transmission by conjugation. (09 Oct 1997) |
| crown gall plasmid | A plasmid, or type of circular DNA, found in the bacteria Agrobacterium tumefaciens which infects dicot plants. Part of the plasmid inserts itself into the plant genome and causes tumours to form in the roots or in the stems nearest the roots. The plasmid has been used by geneticists, minus the tumour-causing parts, as a vector towards the genetic engineering of plants. (09 Oct 1997) |
| cryptic plasmid | A plasmid which has no apparent effect on the phenotype of its host cell and has no genes other than the ones needed for itself to replicate and spread to other cells. (09 Oct 1997) |