| unsaturated fat | <biochemistry> A fat that contains a carbon-carbon double bond, or a fat containing unsaturated fatty acids, such a fatty acid has double or triple covalent bonds and is thus able to add more atoms. Unsaturated fats are believed to lower blood cholesterol levels and are found at high levels in vegetable oils (olive oil, safflower oil, etc.) As a general rule, unsaturated fats are liquid at room temperature. (09 Oct 1997) |
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| low-fat diet | A diet containing minimal amounts of fat.Diets containing low amounts of fat and cholesterol are designed to reduce the risk of heart disease and, in some cases, cancer. Dozens of such diets have been promulgated, both by medical and lay advisors. Their popularity can be attributed in part to clinical studies that have, since the 1980s, revealed, on the one hand, the hazards of eating high-fat, high-cholesterol foods and, on the other, the benefits of ingesting less saturated fat and LDL (low density lipoprotein) cholesterol. Although coronary deaths have been reduced by roughly 30% since 1970, the aim of health officials is to further reduce heart attack rates. The average cholesterol level among adult Americans has fallen from 213 to 205 mg/dl since 1978. However, the National Cholesterol Education Program recommends that individuals maintain a total cholesterol level of no more than 200 mg/dl, with LDL at less than 130 mg/dl and HDL (high density lipoprotein) around 60 mg/dl. About one-half of American adults exceed those recommendations. Low-fat, low-cholesterol diets are rich in whole grains, fresh fruits and vegetables, and legumes, and limit or exclude consumption of processed oils, dairy products, nuts and seeds, and meats. See atherosclerosis, free radicals. (05 Mar 2000) |
| Aarskog-Scott syndrome | A syndrome of ocular hypertelorism, anteverted nostrils, broad upper lip, saddle-bag scrotum, and laxity of ligaments resulting in genu recurvatum, flat feet, and hyperextensible fingers; X-linked and autosomal dominant forms. Synonym: Aarskog-Scott syndrome. (05 Mar 2000) |
| Aarskog syndrome | <syndrome> Grier et al. (1983) reported father and 2 sons with typical Aarskog syndrome, including short stature, hypertelorism, and shawl scrotum. They tabulated the findings in 82 previous cases. X-linked recessive inheritance has been repeatedly suggested. The family reported by Welch (1974) had affected males in 3 consecutive generations. Thus, there is either genetic heterogeneity or this is an autosomal dominant with strong sex-influence and possibly ascertainment bias resulting from use of the shawl scrotum as a main criterion. Stretchable skin was present in the cases of Grier et al. (1983). Teebi et al. (1993) reported the case of an affected mother and 4 sons (including a pair of monozygotic twins) by 2 different husbands. They suggested that the manifestations were as severe in the mother as in the sons and that this suggested autosomal dominant inheritance. Actually, the mother seemed less severely affected, compatible with X-linked inheritance. Clinical signs: Mild to moderate short stature,normocephaly, Widow's peak hair, maxillary hypoplasia, broad nasal bridge, anteverted nostrils, long philtrum, broad upper lip, curved linear dimple below the lower lip, hypertelorism, ptosis, down-slanted palpebral fissures, ophthalmoplegia, strabismus, hyperopic astigmatism, large cornea, floppy ears, lop-ears,cleft lip/palate, shawl scrotum, saddle-bag scrotum, cryptorchidism, brachydactyly, digital contractures, clinodactyly, mild syndactyly, transverse palmar crease, lymphoedema of the feet, ligamentous laxity, osteochondritis dissecans, proximal finger joint hyperextensibility, flexed distal finger joints, genu recurvatum, flat feet, stretchable skin, cervical spine hypermobility, odontoid anomaly, macrocytic anaemia, hemochromatosis, hepatomegaly, portal cirrhosis, imperforate anus, rectoperineal fistula, interstitial pulmonary disease, sternal deformity. Inheritance: Sex-influenced autosomal dominant form, also X-linked form. (05 Aug 1998) |
| abdominal muscle deficiency syndrome | <syndrome> Congenital absence (partial or complete) of abdominal muscles, in which the outline of the intestines is visible through the protruding abdominal wall; in males, genitourinary anomalies (urinary tract dilation and cryptorchidism) are also found; genetics unclear. (05 Mar 2000) |
| abstinence syndrome | <syndrome> A constellation of physiologic changes undergone by persons or animals who have become physically dependent on a drug or chemical due to prolonged use at elevated doses, but who are abruptly deprived of that substance. The abstinence syndrome varies with the drug to which dependence has developed. Generally the effects observed are in an opposite direction from those produced by the drug; e.g., the withdrawal syndrome from central nervous system depressants such as barbiturates and benzodiazepines consists of insomnia, restlessness, tremulousness, hallucinations, and, in the extreme, tonic-clonic convulsions which may prove fatal. The onset time and severity of the abstinence syndrome depend upon how rapidly the drug disappears from the body. (05 Mar 2000) |
| Achard syndrome | <syndrome> Arachnodactyly with small receding mandible, broad skull, and joint laxity limited to the hands and feet; genetics unclear. (05 Mar 2000) |
| Achard-Thiers syndrome | <syndrome> One form of a virilizing disorder of adrenocortical origin in women, characterised by masculinization and menstrual disorders in association with manifestations of diabetes mellitus, such as glucosuria. (05 Mar 2000) |
| Achenbach syndrome | <syndrome> Haematoma of the finger pad with accompanying oedema; of unknown cause in the absence of disturbances in blood coagulation mechanisms. (05 Mar 2000) |
| achoo syndrome | <syndrome> A disorder characterised by nearly uncontrollable paroxysms of sneezing provoked in a reflex fashion by the sudden exposure of a dark-adapted subject to intensely bright light, usually sunlight. Inheritance: autosomal dominant. (05 Aug 1998) |
| Acquired Immunodeficiency Syndrome | <immunology, syndrome> An epidemic disease caused by an infection by human immunodeficiency virus (HIV-1, HIV-2), a retrovirus that causes immune system failure and debilitation and is often accompanied by infections such as tuberculosis. AIDS is spread through direct contact with bodily fluids. Acronym: AIDS (10 May 1997) |
| acrofacial syndrome | Mandibulofacial dysostosis associated with malformations of the extremities such as defective radius and thumbs, and radioulnar synostosis. See: Treacher Collins' syndrome Synonym: acrofacial syndrome. Origin: dys-+ G. Osteon, bone, + -osis, condition (05 Mar 2000) |
| acroparesthesia syndrome | <syndrome> Abnormal sensation such as numbness and tingling in the hands, usually in middle-aged women; classic symptom of carpal tunnel syndrome. (05 Mar 2000) |
| acth syndrome, ectopic | Symptom complex due to acth production by non-pituitary neoplasms. (12 Dec 1998) |
| acute brain syndrome | <syndrome> A condition of severe confusion or rapid change in brain function. This often occurs as the result of a mental illness or physical illness. Symptoms include lethargy, agitation, confusion, disorientation and delirium. (27 Sep 1997) |