2018职称英语新增文章:The,Enemy,Within
时间:2020-02-20 08:45:26 来源:小苹果范文网 本文已影响 人
Allergy is a reaction that occurs when the immune system has astrange unnecessary reaction to a substance which is nmally harmless,such as pollen peanuts. ____1____ To defend your body against an attacker,the immune system remembers these dangerous micro-ganisms attacks them ifit meets them again. This wk is done by antibodies. The immune system inallergy sufferers makes antibodies against harmless substances, because itmistakenly believes them to be dangerous.
An allergic reaction may not happen the first time a sufferer meetsan allergen (the substance causing the reaction, such as pollen, milk strawberries). Sometimes people can eat nuts f years then suddenly becomeallergic to them. What has happened is that the immune system has now decidedthe substance is dangerous has made an allergy antibody. This antibody thenattaches itself to cells, which contain histamine. ____2____ As they do that,the surface of the cells is broken, histamine is released. The histamine other chemicals inflame the tissues. This leads to the symptoms of allergy,such as swelling, rashes, sneezing, se eyes breathlessness. Anaphylaxisis the most severe allergic reaction of all is most often triggered by wasp bee stings peanuts. This must be treated immediately.
____3____ Some people are bn with the ability to make lots ofallergy antibodies, they are me likely to develop allergies allergicdisders such as hay fever asthma.
____4____ We eat me processed foods, with a wide range of additives colourings; me me people have central heating double glazing,making our houses warmer less draughty-an ideal environment to breed thehouse dust mite.
There may also be a link between allergies antibiotics. At onetime our immune systems were kept busy fighting off disease trying to winthe battle f health, but antibiotics have reduced the amount of wk ourimmune systems have to do. Now experts think they may direct spare energy toharmless substances such as strawberries. ____5____
A good deal of research is being devoted to finding a cure fallergies. Sufferers may be given medicine to control symptoms, they mayalso be offered tests to find out what substances trigger an allergic reactionso that they can avoid contact with these in future.