| host vs graft reaction | The immune responses of a host to a graft. A specific response is graft rejection. (12 Dec 1998) |
|---|---|
| dead-end host | A host from which infectious agents are not transmitted to other susceptible host's. (05 Mar 2000) |
| definitive host | <epidemiology> The host in which a parasite reproduces sexually. (05 Dec 1998) |
| disease, graft-versus-host | A reaction of donated bone marrow against a patient's own tissue. Also called GVHD. (12 Dec 1998) |
| immunocompromised host | A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. (12 Dec 1998) |
| intermediate host | <epidemiology> See vector. (05 Dec 1998) |
| transport host | An intermediate host in which no development of the parasite occurs, although its presence may be required as an essential link in the completion of the parasite's life cycle; e.g., the successive fish host's that carry the plerocercoid of Diphyllobothrium latum, the broad fish tapeworm, to larger food fish eventually eaten by man or other final host's. Synonym: transport host. (05 Mar 2000) |
| type host | <zoology> The host species with which the name-bearing type of a nominal species or subspecies was associated. (09 Jan 1998) |
| final host | <epidemiology> The host in which a parasite reproduces sexually. (05 Dec 1998) |
| acquired mutation | A change in a gene or chromosome that occurs in a single cell after the conception of the individual. That change is then passed along to all cells descended from that cell. Acquired mutations are involved in the development of cancer. (12 Dec 1998) |
| addition-deletion mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |
| addition mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |
| amber mutation | <molecular biology> A mutation from a codon which codes for an amino acid into the amber codon UAG, which normally signals that the translation of mRNA into an amino acid chain should stop. The mutation causes the amino acid chain to stop forming before it is actually completed. (09 Oct 1997) |
| back mutation | <molecular biology> A mutation that causes a mutant gene to revert to its original wild-type base sequence. Compare: forward mutation. (09 Oct 1997) |
| reading-frameshift mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |