| stem and loop structure | <molecular biology> The structure of tRNAs is so termed because it has four base paired stems and three loops (not base paired), one of which contains the anticodon. (18 Nov 1997) |
|---|---|
| stem bronchus | The main bronchus from which the branches of the bronchial tree arise. (05 Mar 2000) |
| stem cells | Relatively undifferentiated cells of the same lineage (family type) that retain the ability to divide and cycle throughout postnatal life to provide cells that can become specialised and take the place of those that die or are lost. (12 Dec 1998) |
| stem-clasping | <botany> Embracing the stem with its base; amplexicaul; as a leaf or petiole. Source: Websters Dictionary (01 Mar 1998) |
| infundibular stem | The neural component of the pituitary stalk that contains nerve tracts passing from the hypothalamus to the pars nervosa. Synonym: infundibular stalk. (05 Mar 2000) |
| tumour stem cells | <cell biology> Colony-forming cells which give rise to neoplasms. (12 Dec 1998) |
| acquired platelet function defect | <haematology> Platelet function can be affected by a number of different disease processes including polycythaemia vera, leukaemia, myelofibrosis, renal failure, multiple myeloma and some medications (for example penicillins, salicylates, phenothiazines). Disturbed blood clotting can be manifested by: easy bruising, bleeding gums, nosebleeds, abnormal vaginal bleeding, rectal bleeding, skin rash, vomiting blood, coughing up blood or blood in the urine. A measure of bleeding time and coagulation profile will be part of the evaluation. (29 Dec 1997) |
| aortic septal defect | A small congenital opening between the aorta and pulmonary artery about 1 cm above the semilunar valves, e.g., aorticopulmonary window. Synonym: aorticopulmonary window. (05 Mar 2000) |
| aortopulmonary septal defect | A congenital anomaly in which there is abnormal communication between the ascending aorta and pulmonary artery just above the semilunar valves. (12 Dec 1998) |
| atrial septal defect | <cardiology> An inherited condition where there is nonclosure of the foramen ovale at birth, resulting in congenital heart disease. Usually asymptomatic until the third or fourth decades of life. Symptoms include exertional shortness of breath, fatigue and palpitations. Acronym: ASD (12 Jan 1998) |
| atrial ventricular canal defect | A defect caused by deficient or absent septal tissue immediately above and below the normal level of the atrioventricular valves, including the region normally occupied by the A-V septum in hearts with two ventricles. The A-V valves are abnormal to a varying degree. (05 Mar 2000) |
| birth defect | Defect present at birth; sometimes referred to as congenital defect. (05 Mar 2000) |
| ventricular septal defect | <cardiology, embryology> A congenital heart defect where an abnormal opening exists in the ventricular septum. Blood flows from the higher pressure left ventricle (through the defect) into the right ventricle. (12 Jan 1998) |
| Gerbode defect | <cardiology, embryology> A defect in the interventricular portion of the membranous septum, associated with a communication between the right ventricle and the right atrium through an abnormality in the tricuspid valve. (05 Mar 2000) |
| mass defect | <chemistry, radiobiology> Of a nucleus, the difference between the sum of the masses of the constituent nucleons and the mass of the nucleus. (16 Dec 1997) |