| site-specific DNA-methyltransferase (adenine-specific) | <enzyme> An enzyme responsible for producing a species-characteristic methylation pattern on adenine residues in a specific short base sequence in the host cell DNA. The enzyme catalyses the methylation of DNA adenine in the presence of s-adenosyl-l-methionine to form DNA containing 6-methylaminopurine and s-adenosyl-l-homocysteine. Registry number: EC 2.1.1.72 (12 Dec 1998) |
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| site-specific DNA methyltransferase (cytosine-specific) | <enzyme> An enzyme responsible for producing a species-characteristic methylation pattern on cytosine residues in a specific short base sequence in the host cell's DNA. The enzyme catalyses the methylation of DNA cytosine in the presence of s-adenosyl-l-methionine to form s-adenosyl-l-homocysteine and DNA containing 5-methylcytosine. Registry number: EC 2.1.1.73 (12 Dec 1998) |
| partial denture retention | The fixation of a removable partial denture by the use of clasps, indirect retainers, or precision attachments. (05 Mar 2000) |
| retention | 1. The persistent keeping within the body of matters normally excreted. 2. In cavity preparation, the prevention of displacement of a restoration. 3. <dentistry> The period during which the patient is wearing an appliance to maintain and stabilise the teeth in the position into which they were moved. 4. <psychology> The persistence to perform a learned behaviour (facts or experiences) after an interval has elapsed in which there has been no performance or practice of the behaviour. Origin: L. Retentio, from retentare = to hold firmly back (18 Nov 1997) |
| retention area | An area of a tooth provided during its preparation for restoration that will aid in holding the restoration in place. See: retention groove, retention point. (05 Mar 2000) |
| retention arm | A flexible segment of a removable partial denture that engages an undercut on an abutment and is designed to retain the denture. (05 Mar 2000) |
| retention cyst | A cyst resulting from some obstruction to the excretory duct of a gland. Synonym: distention cyst, secretory cyst. (05 Mar 2000) |
| retention form | The shape of a cavity preparation that prevents displacement of the dental restoration by lateral or tipping forces as well as masticatory forces. (05 Mar 2000) |
| retention groove | One of the groove's forming opposing vertical constrictions in a tooth to aid in retention of a dental restoration. (05 Mar 2000) |
| retention jaundice | Jaundice due to insufficiency of liver function or to an excess of bile pigment production; the bilirubin is unconjugated because it has not passed through the liver cells; van den Bergh test is indirect. (05 Mar 2000) |
| retention point | A provision made within a cavity preparation of a tooth to hold in place the first pieces of gold when placing a direct gold restoration. (05 Mar 2000) |
| retention polyp | A smoothly rounded mucosal hamartoma of the large bowel, which may be multiple and cause rectal bleeding, especially in the first decade of life; it is not precancerous. Synonym: retention polyp. (05 Mar 2000) |
| retention suture | <surgery> A heavy reinforcing suture placed deep within the muscles and fasciae of the abdominal wall to relieve tension on the primary suture line and thus obviate postoperative wound disruption. Synonym: tension suture. (05 Mar 2000) |
| retention vomiting | <gastroenterology, physiology> Vomiting due to mechanical obstruction, usually hours after ingestion of a meal. (05 Mar 2000) |
| chylomicron retention disease | An inherited disorder in which apolipoprotein B-48 is retained in intestine and absent in plasma; results in fat malabsorption. (05 Mar 2000) |