From VOA Learning English, this is Science in the News. I'm Mario Ritter.
And I'm Avi Arditti. Today, we tell the story of aspirin.
People have known1 since ancient times2 that aspirin helps to reduce pain3
And I'm Avi Arditti. Today, we tell the story of aspirin.
People have known1 since ancient times2 that aspirin helps to reduce pain3
and high body temperature. But that is not all4 aspirin can do. It has gained5 important new uses in recent years. Small amounts6 of the drug may help prevent7 a heart attack8 or stroke9.
One study showed that10 some people who took11 two aspirin pills12 a day13
One study showed that10 some people who took11 two aspirin pills12 a day13
had lower rates14 of colorectal cancer.
And researchers say aspirin may help patients with colon cancer live longer15. But others say the acid in aspirin can cause bleeding16 in the stomach and intestines.
And studies showed that aspirin or other pain medicines17 may lead to18 loss of eyesight and hearing19.
So, how did aspirin become20 so important? The story begins with a willow tree21. Two thousand years ago, the Greek doctor22 Hippocrates advised23 his patients to chew on24 the bark25 and leaves26 of the willow. The tree contains27 the chemical salicin. In the 1800s, researchers discovered how to make salicylic acid from salicin. In 1897, a chemist named28
So, how did aspirin become20 so important? The story begins with a willow tree21. Two thousand years ago, the Greek doctor22 Hippocrates advised23 his patients to chew on24 the bark25 and leaves26 of the willow. The tree contains27 the chemical salicin. In the 1800s, researchers discovered how to make salicylic acid from salicin. In 1897, a chemist named28
Felix Hoffmann at Friedrich Bayer and Company in Germany29 created acetyl salicylic acid. Later, it became30 the active
substance in a medicine that Bayer called aspirin.
In 1982, a British scientist shared31 the Nobel Prize32 in Medicine in part for discovering how aspirin works33. Sir John Vanefound that aspirin blocks34 the body from making natural substances called prostaglandins. Prostaglandins have several effects35 on the body. Some cause pain and the expansion, or swelling36, of damaged tissue37.
In 1982, a British scientist shared31 the Nobel Prize32 in Medicine in part for discovering how aspirin works33. Sir John Vanefound that aspirin blocks34 the body from making natural substances called prostaglandins. Prostaglandins have several effects35 on the body. Some cause pain and the expansion, or swelling36, of damaged tissue37.
Others protect the lining38 of the stomach and small intestine. Prostaglandins make the heart, kidneys39 and blood vessels40 work well41.
But there is a problem42. Aspirin works against43 all prostaglandins, good and bad. Scientists have also learned44 how aspirin interferes with an enzyme. One form of this enzyme makes the prostaglandin that causes pain and swelling.
But there is a problem42. Aspirin works against43 all prostaglandins, good and bad. Scientists have also learned44 how aspirin interferes with an enzyme. One form of this enzyme makes the prostaglandin that causes pain and swelling.
Another form creates a protective effect. So aspirin can reduce pain and
swelling in damaged tissues. But it can also harm45 the inside of the stomach and small intestine. And sometimes46 it can cause bleeding.
Many people take aspirin47 to reduce the risk of a heart attack or stroke from blood clots48. Clots can block the flow of blood49 to the heart or brain50 and cause a heart attack or stroke. Scientists say aspirin prevents51 blood cells called platelets from sticking together52 to form clots.
A California doctor named Lawrence Craven first reported this effect in the 1950s. He observed unusual bleeding53 in children who chewed on an aspirin product to ease the pain54 after a common operation. Doctor Craven believed the bleeding took place55 because aspirin prevented blood from thickening56. He thought56 this effect might help prevent heart attacks caused by blood clots. He examined the medical records of 8,000 aspirin users57 and found no heart attacks in this group. He invited58 other scientists to test his ideas. But it was years before large studies took place.
Many people take aspirin47 to reduce the risk of a heart attack or stroke from blood clots48. Clots can block the flow of blood49 to the heart or brain50 and cause a heart attack or stroke. Scientists say aspirin prevents51 blood cells called platelets from sticking together52 to form clots.
A California doctor named Lawrence Craven first reported this effect in the 1950s. He observed unusual bleeding53 in children who chewed on an aspirin product to ease the pain54 after a common operation. Doctor Craven believed the bleeding took place55 because aspirin prevented blood from thickening56. He thought56 this effect might help prevent heart attacks caused by blood clots. He examined the medical records of 8,000 aspirin users57 and found no heart attacks in this group. He invited58 other scientists to test his ideas. But it was years before large studies took place.
Charles Hennekens of Harvard Medical School led59 one of the studies. In 1983, he began to study60 more than 22,000 healthy61 male62 doctors over63 40 years of age. Half64 took an aspirin
every other day65. The others took what they thought66 was aspirin. But it was only a placebo, an inactive substance. Five years later, Dr. Hennekens reported that67 people
who took aspirin reduced their risk of a heart attack. But they had a higher68 risk of bleeding in the brain than the other doctors.
Vocabulary
1. have known = têm sabido
2. since ancient times = desde épocas remotas
3. reduce pain = reduzir a dor
4. that is not all = isso não é tudo
5. has gained = tem ganhado
6. Small amounts = pequenas quantidades
7. may help prevent = pode ajudar a prevenir
8. heart attack = ataque cardiac
9. stroke = derrame
10. showed that = mostrou que
11. people who took = pessoas que tomavam
12. pills = comprimidos
13. a day = por dia
14. lower rates = indices mais baixos
15. live longer = viver mais tempo
16. can cause bleeding = podem causar hemorragia
17. medicines = remedies
18. may lead to = podem conduzir a
19. loss of eyesight and hearing = perda da visão e audição
20. become = tornar-se
21. willow tree = salgueiro
22. Greek doctor = medico Grego
23. advised = aconselhava
24. chew on = mastigar
25. bark = casca
26. leaves = folhas
27. leaves = contém
28. a chemist named = um químico chamado
29. Germany = Alemanha
30. became = tornou-se
31. shaured = dividiu, compartilhou
32. Nobel Prize = Prêmio Nobel
33. how aspirin works = como a aspirina funciona
34. blocks = bloqueia, impede
35. several effects = diversos efeitos
36. swelling = inchaço
37. damaged tissue = tecido danificado
38. lining = revestimento
39. kidneys = rins
40. blood vessels = vasos sanguineos
41. work well = funciona bem
42. there is a problem = há um problema
43. against = contra
44. have also learned = tem tambem aprendido
45. harm = prejudicar, fazer mal
46. sometimes = às vezes
47. take aspirin = tomam aspirina
48. blood clots = coágulos sanguineos
49. flow of blood = fluxo de sangue
50. brain = cérebro
51. prevents= previne
52. sticking together = juntar-se
53. unusual bleeding = hemorragia incomum
54. ease the a = amenizar a dor
55. thickening = engrossar
56. thought = pensou
57. users = usuarios
58. invited = convidou
59. led = liderou
60. began to study = começou a estudar
61. healthy = saudável
62. male = do sexo masculino
63. over = acima de
64. Half = metade
65. every other day = dia sim, dia não, em dias alternados
66. thought = pensou. Achou
67. reported that = relatou que
68. higher = mais alto
