Precursor of Vitamin A. Increases resistance against infection. Antioxidant. Together with Vitamins C and E form a vital line of defence in protection of strands of DNA, the genetic code, from cancerous mutation. Immune booster. Increases lymphocytes and T cells, part of the defence system.
Deficiency. Sun sensitivity; exposure inducing itching, burning and swelling of the skin. Kidney, bladder, and gut infections. Severe earache in young children. Strokes, heart attacks.
It is claimed that those who eat a diet rich in beta-carotene are less likely to develop certain types of cancer.
Smokers usually have low levels of beta-carotene in the blood. Statistics suggest that people who eat a lot of beta-carotene foods are less likely to develop lung, mouth or stomach cancer. In existing cases a slow-down of the disease is possible.
Daily dose. Up to 300mg. Excess may manifest as yellow discoloration of the skin, giving appearance of sun-tan.
Sources. Mature ripe carrots of good colour. A Finland study suggests that four small carrots contain sufficient beta-carotene to satisfy the recommended daily amount of Vitamin A. Orange and dark green fruits and vegetables. Broccoli, Brussels sprouts, spinach, pumpkin, apricots, peaches, oranges, tomatoes. Harvard Medical School study. Among 333 subjects with a history of heart disease, those who received beta-carotene supplements of 50 milligrams every other day suffered half as many heart attacks as those taking placebos. (Dr Charles Hennekens, Harvard Medical School)
A colouring matter of carrots, other plants, butter and yolk of egg, carotene is the precursor of vitamin A, which is formed from carotene in the liver. (See VITAMIN and APPENDIX 5: VITAMINS.)... carotene
(beta-adrenergic receptor blocker) a drug that prevents stimulation of the beta *adrenoceptors at the nerve endings of the sympathetic nervous system. Blockade of ?1 receptors causes a decrease in heart rate and force; blockade of ?2 receptors causes constriction of the airways and the arteries. Beta blockers include *acebutolol, *atenolol, *bisoprolol, *oxprenolol, *propranolol, and *sotalol; they are used to control abnormal heart rhythms, to treat angina, and to reduce high blood pressure (although they are no longer regarded by some experts as the first choice of drug for treating hypertension in the absence of heart disease, being less effective than newer antihypertensive drugs). Beta blockers that block both ?1 and ?2 receptor sites cause constriction of air passages in the lungs, and these drugs should not be used in patients with asthma and bronchospasm. Other beta blockers are relatively selective for the heart (cardioselective) and are less likely to constrict the airways. Some beta blockers (e.g. *carteolol, *levobunolol, and *timolol) reduce the production of aqueous humour and therefore the pressure inside the eye; they are taken as eye drops in the treatment of *glaucoma.... beta blocker
one of a group of drugs that includes the *penicillins and the *cephalosporins. All have a four-membered beta-lactam ring as part of their molecular structure. Beta-lactam antibiotics function by interfering with the growth of the cell walls of multiplying bacteria. Bacteria become resistant to these antibiotics by producing beta-lactamases, enzymes (such as *penicillinase) that disrupt the beta-lactam ring. To counteract this, beta-lactamase inhibitors (e.g. *clavulanic acid) may be added to beta-lactam antibiotics. For example, co-amoxiclav is a mixture of *amoxicillin and clavulanic acid.... beta-lactam antibiotic
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